JP2023031589A - Photothermal conversion analyzer and initial deterioration analysis method - Google Patents

Abstract

To provide a photothermal conversion analyzer capable of detecting slight chemical change with high sensitivity even when a surface of an opaque sample is uneven.SOLUTION: A photothermal conversion analyzer comprises a first light source unit, a second light source unit, an objective lens, a filter, and a detection unit. The first light source unit emits excitation light for generating a thermal lens to an opaque sample. The second light source unit emits probe light reflected from the opaque sample. The objective lens converges the incident excitation light and probe light toward an analysis area of the opaque sample, and emits reflected light including the probe light reflected by the opaque sample. The filter transmits transmitted light that blocks the excitation light in the reflected light. The detection unit receives the transmitted light, and detects a thermal lens signal of the transmitted light.SELECTED DRAWING: Figure 1

Description

The present invention relates to a photothermal conversion analysis device and an initial deterioration analysis method.

In recent years, with the development of new materials and the like, there is a demand for an analysis method that enables in situ measurement and can detect slight chemical changes with high sensitivity. Thermal lens spectroscopy and the Mirage method are known as such analysis methods.

Thermal lens spectroscopy is a method that mainly utilizes the thermal lens effect that occurs inside a transparent sample due to heat due to non-radiative relaxation that occurs when the transparent sample is irradiated with excitation light. The thermal lens effect shows that the distribution of refractive index occurs according to the distribution of heat, and it mainly works in the same way as a concave lens. The sensitivity of thermal lens spectroscopy is known to be over 100 times higher than that of absorptiometry.
Patent Literature 1 discloses a reflective thermal lens spectroscopic analyzer using thermal lens spectroscopy. In the apparatus disclosed in Patent Document 1, probe light is incident on a thermal lens generated inside a transparent sample due to incidence of excitation light. analysis. The apparatus disclosed in Patent Document 1 includes a sample cell, retroreflection means, and detection means. A sample cell contains a transparent sample. The retroreflection means receives the probe light that has passed through the thermal lens and the sample cell, and reflects the probe light in the direction of incidence. The detection means detects the probe light reflected by the retroreflection means.

The Mirage method is a method that mainly utilizes the thermal lens effect (hereinafter sometimes referred to as "mirage phenomenon") generated in the air near the sample due to heat due to non-radiative relaxation generated when the sample is irradiated with excitation light. (For example, Non-Patent Document 1, Non-Patent Document 2, etc.).
Specifically, when a sample is irradiated with excitation light, the sample absorbs the excitation light and emits heat due to non-radiative relaxation. The heat radiated from the sample is transmitted to the air near the sample, and a mirage phenomenon occurs in the air. When the probe light is passed along the surface of the sample so that the probe light passes through the region where the mirage phenomenon occurs, the probe light does not travel straight but is deflected. The in-plane direction of the surface of the sample indicates all directions along a plane substantially parallel to the surface of the sample. In the Mirage method, slight chemical changes in the sample are detected with high sensitivity by detecting the magnitude of this deflection (Mirage effect).

JP 2004-286578 A

Edited by Akira Harada, ``Laser spectroscopic analysis'', Maruzen Co., Ltd., June 2009, pp.9-12 Yukimasa Kure, 3 others, "Chemical Reaction Measurement by Thermal Beam Deflection Measurement Method", Japan Thermal Measurement Society, 1995, vol.20, No.3, p.143-150 Kazuma Mawatari, 6 others, "Thermal Lens Microscope", Journal "Optics", Subcommittee, The Optical Society of Japan, 2004, Vol.33, No.12, p.708-714

However, if the sample is an opaque sample, thermal lens spectroscopy may not be able to sufficiently transmit the probe light inside the opaque sample and may not be able to detect slight chemical changes in the opaque sample with high sensitivity. be.
Also, the mirage phenomenon decays exponentially with distance from the sample surface. Therefore, in the Mirage method, if the surface of the opaque sample has unevenness (for example, the difference between the unevenness of the convex portion and the concave portion is 1 μm or more), the presence of the unevenness causes the probe light to enter the region where the thermal lens effect occurs. It is difficult to detect small chemical changes in transparent samples with high sensitivity.
Therefore, there is a demand for a photothermal conversion analyzer that can detect slight chemical changes in an opaque sample with high sensitivity even if the surface of the opaque sample has unevenness.

On the other hand, Patent Literature 1, Non-Patent Literature 1, and Non-Patent Literature 2 do not describe any method for analyzing the initial deterioration of a sample. In order to make it easier to predict sample degradation and take measures to prevent degradation, there is a demand for an initial degradation analysis method capable of detecting the occurrence of initial degradation of a sample with high sensitivity.

The present disclosure has been made in view of the above.
A problem to be solved by an embodiment of the present disclosure is to provide a photothermal conversion analyzer capable of detecting slight chemical changes with high sensitivity even if the surface of an opaque sample has unevenness.
A problem to be solved by another embodiment of the present disclosure is to provide an initial deterioration analysis method capable of detecting the occurrence of initial deterioration of a sample with high sensitivity.

Means for solving the above problems include the following embodiments.

<1> The photothermal conversion analyzer of the first aspect of the present disclosure includes a first light source unit that emits excitation light for generating a thermal lens effect on an opaque sample, and a probe light that is reflected on the opaque sample. and an objective lens for condensing the incident excitation light and the probe light toward an analysis area of the opaque sample and emitting reflected light including the probe light reflected by the opaque sample. and a filter that transmits transmitted light that blocks the excitation light among the reflected light, and a detector that receives the transmitted light and detects a thermal lens signal of the transmitted light. be.

In the present disclosure, an analysis area of an opaque sample refers to at least a portion of the surface of the opaque sample.

In the first aspect, the objective lens converges the excitation light and the probe light toward the analysis area of the opaque sample and emits reflected light including the probe light reflected from the opaque sample. Opaque samples absorb irradiated excitation light and radiate heat. This creates a thermal lensing effect in the air in the vicinity of the opaque sample. In a first aspect, probe light is focused by an objective lens onto an analysis area of an opaque sample. Therefore, unlike the conventional Mirage method, the probe light passes through the area where the thermal lens effect occurs, even if the probe light does not pass along the surface of the sample and just above the surface of the sample. The probe light is deflected by thermal lensing. In this case, small chemical changes in the opaque sample change the magnitude of deflection of the probe light. Since the photothermal conversion analysis apparatus of the first aspect includes the filter and the detection unit, it is possible to accurately detect changes in the magnitude of deflection of the probe light due to the thermal lens effect. As a result, the photothermal conversion analyzer of the first aspect can detect slight chemical changes in an opaque sample with high sensitivity even if the surface of the opaque sample has unevenness.

<2> In the photothermal conversion analysis device of the second aspect of the present disclosure, the second light source unit has an incident position adjusting unit that adjusts the incident position of the probe light on the objective lens, and the incident position adjusting unit and The photothermal conversion analyzer according to <1>, wherein the objective lens is adjusted so that the probe light is obliquely incident on the surface of the opaque sample.

In a second aspect, the distance through which the probe light focused by the objective lens toward the analysis area of the opaque sample and reflected by the opaque sample passes through the area where the thermal lens effect is occurring is longer than if it were aligned to be incident normal to the surface of the sample. This makes the probe light more likely to be deflected by the thermal lens effect. As a result, the photothermal conversion analyzer of the first aspect can detect slight chemical changes in an opaque sample with higher sensitivity even if the surface of the opaque sample has unevenness.

<3> In the photothermal conversion analysis device of the third aspect of the present disclosure, the first light source unit includes a first light source that emits light, and intensity-modulates the light with a predetermined chopping frequency to generate the excitation light. an optical chopper, wherein the detector receives the transmitted light and generates an intensity signal corresponding to the intensity of the transmitted light; The photothermal conversion analyzer according to <1> or <2>, further comprising a synchronous detection circuit for extracting a thermal lens signal.

In the third aspect, by using the chopping frequency of the excitation light as the reference signal for the synchronous detection circuit, the photothermal conversion analyzer can detect weak signals buried in noise. As a result, the photothermal conversion analyzer of the third aspect can detect slight chemical changes in an opaque sample with higher sensitivity even if the surface of the opaque sample has irregularities.

<4> A photothermal conversion analyzer according to a fourth aspect of the present disclosure is the photothermal conversion analyzer according to any one of <1> to <3>, wherein the objective lens is a reflective objective lens.

A reflective objective lens hardly absorbs light whose wavelength is in the visible range or the near-infrared range. Therefore, the photothermal conversion analyzer of the fourth aspect can detect slight chemical changes in the opaque sample with higher sensitivity even when the opaque sample absorbs excitation light in the visible range or the near-infrared range. can.

<5> The photothermal conversion analysis apparatus of the fifth aspect of the present disclosure includes a stage on which the opaque sample is placed, a driving unit that moves the stage with respect to the objective lens, a control unit, and the control The photothermal conversion analysis apparatus according to any one of <1> to <4>, wherein the unit controls the drive unit and the detection unit to acquire the thermal lens signal for each of the plurality of analysis regions. is.

In the fifth aspect, the photothermal conversion analyzer can automatically acquire the thermal lens signal of each of the plurality of analysis regions. As a result, the photothermal conversion analyzer of the fifth aspect can efficiently detect slight chemical changes in opaque samples. Therefore, the photothermal conversion analysis device of the fifth aspect can be used as a microscopic imaging device.

<6> The initial deterioration analysis method of the sixth aspect of the present disclosure includes a first thermal lens signal detection step of detecting a first thermal lens signal in an analysis region of an unaged specimen of the sample, and the analysis of the aged specimen of the specimen. a second thermal lens signal detecting step of detecting a second thermal lens signal of the area; and whether or not the analysis area of the aging product has deteriorated based on the first thermal lens signal and the second thermal lens signal. In the first thermal lens signal detection step, the excitation light is incident on the objective lens to generate the first thermal lens effect in the non-aging product, and the probe light is emitted to the The first light including the probe light that is incident on the objective lens and condensed on the analysis region of the non-aged product and transmitted or reflected by the non-aged product via the first thermal lens effect is converted into the excitation light. The first thermal lens signal is detected from the first transmitted light, and in the second thermal lens signal detection step, the excitation light is directed to the objective lens. incident to generate a second thermal lens effect on the aged product, the probe light incident on the objective lens to focus on the analysis region of the aged product, and the aged product via the second thermal lens effect; A method for analyzing initial deterioration, comprising passing through the filter the second light containing the probe light that is transmitted or reflected by the product, emitting the second transmitted light, and detecting the second thermal lens signal from the second transmitted light. is.

In the present disclosure, "sample" includes opaque and transparent samples.
Immediately after production, the samples are carefully stored so that they are not subject to deterioration such as heat, oxidation, or shear. In the present disclosure, the "non-aged sample product" refers to the sample immediately before the start of use or processing, etc., and the "aged sample product" is a sample that is not a non-aged product of the sample. Show things.

In the sixth aspect, based on the first thermal lens signal of the analysis area of the non-aged sample and the second thermal lens signal of the analysis area of the aged sample, the analysis area of the aged sample is degraded. As a result, the initial deterioration analysis method of the sixth aspect can detect the occurrence of initial deterioration of the sample with high sensitivity.

<7> The initial deterioration analysis method of the seventh aspect of the present disclosure includes: a first reference signal detection step of detecting a first reference signal in the analysis region of the non-aged product; a first normalized signal calculating step of calculating a first normalized signal indicating a lens signal ratio; a second reference signal detecting step of detecting a second reference signal of the analysis region of the aging product; a second normalized signal calculating step of calculating a second normalized signal indicating a ratio of the second thermal lens signal to the second thermal lens signal; Based on the first normalized signal and the second normalized signal instead of, the control unit determines whether the analysis region of the aged product is degraded, and in the first reference signal detection step, The excitation light is not incident on the objective lens, the probe light is incident on the objective lens to be focused on the analysis region of the non-aged product, and the probe light transmitted or reflected by the non-aged product is included. passing the third light through the filter to emit third transmitted light; detecting the first reference signal from the third transmitted light; without entering the probe light into the objective lens and focused on the analysis region of the aged product, and the fourth light including the probe light transmitted or reflected by the aged product passes through the filter The initial deterioration analysis method according to <6>, wherein the second reference signal is detected from the fourth transmitted light.

In the seventh aspect, the control unit, based on the first normalized signal of the analysis region of the non-aged sample and the second normalized signal of the analysis region of the aged sample, is degraded. Because the first normalized signal is the ratio of the first thermal lens signal to the first reference signal, it more clearly indicates the difference in reflectance of the probe light in the analysis region than the first thermal lens signal alone. The second normalized signal likewise more clearly indicates the difference in reflectance of the probe light in the analysis region than the second thermal lens signal alone. As a result, the initial deterioration analysis method of the sixth aspect can detect the occurrence of initial deterioration of the sample with higher sensitivity.

<8> In the initial deterioration analysis method of the eighth aspect of the present disclosure, in the deterioration determination step, the control unit determines the absolute value of the difference between the first normalized signal and the second normalized signal in the analysis region and determining whether or not the difference value is equal to or greater than a threshold value, and if the difference value is equal to or greater than the threshold value, it is determined that the analysis region of the aging product has deteriorated, and the The initial deterioration analysis method according to <7>, wherein if the difference value is not equal to or greater than a threshold value, it is determined that the analysis region of the aging product has not deteriorated.

Deterioration of a specimen over time may be such that the thermal lens signal becomes stronger as the deterioration progresses, or the thermal lens signal becomes weaker as the deterioration progresses. In the eighth aspect, the difference value indicates the absolute value of the difference between the first normalized signal of the analysis area of the non-aged opaque sample and the second normalized signal of the analysis area of the aged opaque sample. As a result, in the initial deterioration analysis method of the eighth aspect, the analysis area of the aging product of the sample is determined whether the thermal lens signal becomes stronger as the deterioration progresses or the thermal lens signal becomes weaker as the deterioration progresses. Even if there is, the occurrence of initial deterioration of the sample can be detected with high sensitivity.

<9> In the initial deterioration analysis method of the ninth aspect of the present disclosure, the analysis area includes a plurality of minute areas, and in the first thermal lens signal detection step, each of the plurality of minute areas of the non-aging product detecting the first thermal lens signal of the first reference signal detecting step, detecting the first reference signal of each of the plurality of minute regions of the non-aging product, and calculating the first normalized signal Then, for each of the plurality of minute regions, the first normalized signal of the corresponding minute region is calculated, and in the second thermal lens signal detecting step, the first detecting two thermal lens signals; in the second reference signal detecting step, detecting the second reference signal for each of the plurality of minute regions of the aged product; and in the second normalized signal calculating step, the plurality of calculating the second normalized signal of the corresponding minute area for each of the minute areas, and in the deterioration determining step, based on the plurality of first normalized signals and the plurality of second normalized signals The initial deterioration analysis method according to <7>, wherein it is determined whether or not each of the plurality of minute regions of the aging product is deteriorated.

In the present disclosure, "the first normalized signal of the corresponding minute area" means the minute area where the first thermal lens signal is detected and the first reference signal is detected when calculating the first normalized signal. It indicates that the minute area is the same.
In the present disclosure, "the second reference signal of the corresponding minute area" means the minute area where the second thermal lens signal is detected and the minute area where the second reference signal is detected when calculating the second normalized signal. Indicates that the region is the same.

Initial deterioration of a sample tends to occur gradually from weaker micro-sites of the sample than from uniform micro-sites. In the eighth aspect, the analysis region includes a plurality of minute regions, and the control unit determines whether each of the plurality of minute regions has deteriorated. As a result, the initial deterioration analysis method of the ninth aspect can detect the occurrence of initial deterioration of the sample with higher sensitivity.

<10> In the initial deterioration analysis method of the 10th aspect of the present disclosure, in the deterioration determination step, for each of the plurality of minute regions, the controller controls the first normalized signal of the corresponding minute region and the first 2 calculating a difference value indicating an absolute value of a difference from the normalized signal, determining whether or not the difference value is equal to or greater than a threshold value, and determining whether the difference value is equal to or greater than the threshold value; The initial deterioration analysis method according to <9>, wherein it is determined that the minute area is degraded, and if the difference value is not equal to or greater than a threshold value, the corresponding minute area of the aged product is determined not to be degraded. be.

In the present disclosure, "the difference between the first normalized signal and the second normalized signal of the corresponding minute area" means a minute area (hereinafter referred to as (referred to as “first region”)) and the first normalized signal of a small region corresponding to the first region of the non-aged opaque sample among aged opaque samples.

As described above, the deterioration of a specimen over time may be such that the thermal lens signal becomes stronger as the deterioration progresses, or the thermal lens signal becomes weaker as the deterioration progresses. In the tenth aspect, the difference value indicates the absolute value of the difference between the first normalized signal of the corresponding minute region of the non-aged sample and the second normalized signal of the corresponding minute region of the aged sample. . As a result, in the initial deterioration analysis method of the tenth aspect, for each of the plurality of minute regions of the aged specimen, the thermal lens signal becomes stronger as the deterioration progresses and the thermal lens signal becomes weaker as the deterioration progresses. In either case, the occurrence of initial deterioration of the sample can be detected with high accuracy.

<11> In the initial deterioration analysis method of the eleventh aspect of the present disclosure, the initial deterioration according to <9> or <10>, wherein the minute area is a square area having a side length of 1 μm or more and less than 100 μm. Analysis method.

The initial deterioration analysis method of the eleventh aspect can more accurately detect whether or not initial deterioration of the sample has occurred.

<12> In the initial deterioration analysis method of the twelfth aspect of the present disclosure, the sample is an opaque sample, and each of the first light and the third light is reflected on the non-aged product and the second The initial deterioration analysis method according to any one of <7> to <11>, wherein each of the light and the fourth light is reflected on the aged product.

The initial deterioration analysis method of the twelfth aspect can detect the occurrence of initial deterioration of the sample with higher sensitivity even if the surface of the opaque sample has unevenness.

According to one embodiment of the present disclosure, a photothermal conversion analyzer is provided that can detect slight chemical changes in an opaque sample with high sensitivity even if the surface of the opaque sample has unevenness.
According to another embodiment of the present disclosure, an initial deterioration analysis method is provided that can detect the occurrence of early deterioration of a sample with high sensitivity.

1 is a configuration diagram showing the configuration of a photothermal conversion analysis device according to a first embodiment of the present disclosure; FIG. (a) is a cross-sectional view showing an example of a reflective objective lens, and (b) is a cross-sectional view showing an example of a refractive objective lens. FIG. 4 is a cross-sectional view showing an example of an optical path of probe light condensed by an objective lens; 1 is a block diagram showing the configuration of a photothermal conversion analysis device according to a first embodiment of the present disclosure; FIG. FIG. 2 is a configuration diagram showing the configuration of a photothermal conversion analysis device according to a second embodiment of the present disclosure; FIG. FIG. 10 is a configuration diagram showing the configuration of a photothermal conversion analysis device according to a third embodiment of the present disclosure;

The content of the present disclosure will be described in detail below.
The description of the constituent elements described below may be made based on representative embodiments of the present disclosure, but the present disclosure is not limited to such embodiments.

In the present disclosure, a numerical range indicated using "to" indicates a range including the numerical values before and after "to" as the minimum and maximum values, respectively.
In the numerical ranges described step by step in the present disclosure, the upper limit value or lower limit value described in a certain numerical range may be replaced with the upper limit value or lower limit value of another numerical range described step by step, and , may be replaced by the values shown in the examples.
In the present disclosure, when there are multiple substances corresponding to each component in the material, the amount of each component in the material means the total amount of the multiple substances present in the material unless otherwise specified.

Hereinafter, embodiments of the photothermal conversion analysis device of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(1) First Embodiment A photothermal conversion analyzer 1A according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 4. FIG.

(1.1) Photothermal Conversion Analyzer As shown in FIG. 1, the photothermal conversion analyzer 1A includes a first light source section 10A, a second light source section 20, a first mirror 31, a dichroic mirror 32, and a second light source section 32. It includes a mirror 33 , an objective lens 40 , a stage device 50 , a third mirror 34 , a pinhole 35 , an optical filter group 60 , a detection section 70A, and an information processing device 80 .
The photothermal conversion analysis apparatus 1A is an apparatus that analyzes an opaque sample 2 by utilizing a thermal lens effect (mirage phenomenon) generated in the air near the opaque sample 2 by heat due to non-radiative relaxation. Specifically, the photothermal conversion analyzer 1A converges the excitation light EL and the excitation light EL for generating a thermal lens effect in the air on the opaque sample 2 via the objective lens 40, and reflects the light from the opaque sample 2. The opaque sample 2 is analyzed based on the magnitude of the thermal lens deflection of the probe beam PL.

The opaque sample 2 contains a specific component to be analyzed (hereinafter referred to as "first detection component") and mainly reflects the probe light PL.
The state of the opaque sample 2 is not particularly limited, and may be solid or liquid. When the opaque sample 2 is solid, the surface of the opaque sample 2 may or may not have an uneven shape. The uneven shape means that the unevenness difference between the convex portion and the concave portion is 0.1 μm or more and is equal to or less than the working distance of the objective lens used.
The first detection component is not particularly limited as long as it absorbs the excitation light EL and generates heat by non-radiative relaxation. The number of first detection components may be one, or two or more. The first detection component may be present on at least one of the surface of the opaque sample 2 and the interior of the opaque sample 2 . Opaque sample 2 may be a product. For example, if the opaque sample 2 is a polyvinyl chloride (PVC) resin molded plate, the first sensing component is PVC.

The first light source unit 10A emits excitation light EL for generating a thermal lens effect on the opaque sample 2 . The first light source section 10A has a first light source 11 , an optical filter 12 and an optical chopper 13 .

The first light source 11 emits a first light L1. The first light L1 includes a wavelength region that is absorbed by the first detection component (hereinafter referred to as "absorption wavelength"). In the first embodiment, the first light L1 is a continuous wave. The first light source 11 is appropriately selected according to the type of the first detection component. When the absorption wavelength is within the range of near-infrared to ultraviolet light, examples of the first light source 11 include a xenon lamp, a tungsten lamp, a halogen lamp, a hollow cathode lamp, and a deuterium lamp. Among them, the first light source 11 is preferably a xenon lamp (wavelength: 200 nm to 2500 nm) from the viewpoint of including all wavelengths from ultraviolet rays to near ultraviolet rays.

The optical filter 12 selectively passes a specific wavelength band including absorption wavelengths in the first light L1 emitted from the first light source 11 . Thereby, the selected light L2 is obtained.
The optical filter 12 is appropriately selected according to the type of the first light source section 10A, the wavelength region of the absorption wavelength, and the like. The optical filter 12 is not particularly limited as long as it can selectively extract a specific wavelength band including absorption wavelengths, and examples thereof include colored glass filters, interference filters, neutral density filters, and the like. The optical filter 12 may be of one type, or may be a combination of two or more types.

The optical chopper 13 intensity-modulates the selected light L2 with a predetermined chopping frequency to generate excitation light EL. In other words, the optical chopper 13 repeats blocking and passage of the selected light L2 at a predetermined chopping frequency, thereby changing the intensity of the selected light L2 transmitted through the optical filter 12 over time into pulses of the chopping frequency. The optical chopper 13 and the synchronous detection circuit 72 are electrically connected.
The chopping frequency is not particularly limited, and is, for example, 5 Hz and 10 Hz.
The optical chopper 13 is not particularly limited, and an example thereof includes an optical chopper that rotates a disc with a large number of slits.

The second light source unit 20 emits probe light PL that is reflected by the opaque sample 2 . The second light source section 20 has a second light source 21 and a prism 22 which is an example of an incident position adjusting section.

The second light source 21 emits the second light L3. The second light L3 includes a wavelength range reflected by the opaque sample 2 . The second light L3 is a continuous wave. The second light source 21 is appropriately selected according to the type of material of the opaque sample 2 and the like. The second light source 21 is not particularly limited, and examples thereof include gas lasers and solid-state lasers. Gas lasers include helium neon laser (fundamental wavelength: ), nitrogen laser, argon laser, krypton laser, excimer laser, helium cadmium laser, copper vapor laser, carbon dioxide laser, and the like. Solid-state lasers include Nd:YAG lasers, Nd:YLF lasers, Nd: _YVO4 lasers, Er:YAG lasers, and the like. Among them, a gas laser is preferable as the second light source 21 from the viewpoint of ease of handling. For example, when the opaque sample 2 is a polyvinyl chloride (PVC) resin molded plate and the first detection component is PVC, the second light source 21 is more preferably a helium neon laser (fundamental wavelength: 633 nm).

The prism 22 adjusts the incident position of the probe light PL on the objective lens 40 by reflecting the second light L3. Also, the prism 22 reflects the reflected light RL emitted from the dichroic mirror 32 and guides the reflected light RL to the third mirror 34 . The prism 22 is not particularly limited as long as it functions as a reflecting member, and examples thereof include a rectangular prism.

The first mirror 31 reflects the excitation light EL and guides the excitation light EL to the dichroic mirror 32 . Examples of the first mirror 31 include a plane mirror, a rear surface mirror, and the like.
The dichroic mirror 32 reflects the excitation light EL, transmits the probe light PL, and emits the excitation light EL and the probe light PL on the same optical axis. Also, the dichroic mirror 32 transmits the reflected light RL guided from the second mirror 33 .
The second mirror 33 reflects the excitation light EL and the probe light PL and guides the excitation light EL and the probe light PL to the objective lens 40 . Also, the first mirror 31 reflects the reflected light RL emitted from the objective lens 40 and guides the reflected light RL to the dichroic mirror 32 . Examples of the second mirror 33 include a plane mirror, a rear surface mirror, and the like.

(1.1.4) Objective lens The objective lens 40 collects the incident excitation light EL and probe light PL toward the analysis area of the opaque sample 2 and includes the probe light PL reflected by the opaque sample 2. It emits reflected light RL. In the first embodiment, there is no focus difference between the excitation light EL and the probe light PL.

Objective lens 40 may be a commercially available product. The structure of the objective lens 40 is appropriately selected according to the respective wavelength bands of the excitation light EL and the probe light PL.
When the excitation light EL and the probe light PL include the ultraviolet region or the infrared region, from the viewpoint of irradiating the opaque sample with the light in the ultraviolet region or the infrared region (i.e., suppressing the absorption of the light in the ultraviolet region or the infrared region by the objective lens 40 from the point of view), the structure of the objective lens 40 is preferably a reflective objective lens 40A as shown in FIG. 2(a). The reflective objective lens 40A has an aspherical reflective mirror 41A, an aspherical reflective mirror 42A, and a housing 43B. The housing 43B accommodates the aspherical reflection mirror 41A and the aspherical reflection mirror 42A.
When the excitation light EL and the probe light PL include the visible range or the near-infrared range, from the viewpoint of irradiating the opaque sample with the light in the visible range or the near-infrared range (that is, the light in the visible range or the near-infrared range by the objective lens 40 From the viewpoint of suppressing absorption), the structure of the objective lens 40 is preferably a refractive objective lens 40B as shown in FIG. 2(b). The refractive objective lens 40B has a lens group 41B and a housing 42B. The housing 42B accommodates the lens group 41B. The lens group 41B includes multiple lenses.

The higher the numerical aperture (NA) of the objective lens 40, the better. As a result, the angle formed by the ray of the probe light PL that passes through the edge of the entrance pupil and the optical axis becomes higher. Therefore, the distance through which the probe light PL passes through the area where the thermal lens effect occurs becomes longer. In other words, the probe light PL is more easily deflected by the thermal lens effect. As a result, the photothermal conversion analyzer 1A can detect slight chemical changes with higher sensitivity.

The prism 22 and the objective lens 40 are adjusted so that the probe light PL is obliquely incident on the surface of the opaque sample 2, as shown in FIG. Specifically, the prism 22 and the objective lens 40 are arranged so that the probe light PL passes through the edge of the entrance pupil.

An opaque sample 2 is placed on the stage device 50 . The stage device 50 is movable and can move with respect to the objective lens 40 .
The stage device 50 has a stage 51 (see FIG. 4) and a driving section 52 (see FIG. 4). The surface of the stage 51 on which the opaque sample 2 is placed is planar. The drive unit 52 moves the stage 51 with respect to the objective lens 40 in the in-plane direction of the stage. The drive unit 52 is electrically connected to the information processing device 80 .

The third mirror 34 reflects the reflected light RL and guides the reflected light RL to the pinhole 35 .
The pinhole 35 has a through hole. The diameter of the through-hole is appropriately selected according to the first detection component and the like, and is, for example, 100 μm. The pinhole 35 allows only the reflected light RL passing through the through hole to pass through the reflected light RL incident from the third mirror 34 . If the amount of deflection of the probe light PL changes due to the thermal lens effect, the amount of light detected by the detector 70A changes. Therefore, the photothermal conversion analyzer 1A can more quantitatively measure the degree of deflection of the probe light PL (the degree of thermal lens effect) from the amount of change in the amount of light detected by the detector 70A.

The optical filter group 60 blocks the excitation light EL of the reflected light RL and transmits the transmitted light TL.
The optical filter group 60 has a low pass filter 61 and a laser line filter 62 .
The low-pass filter 61 selectively transmits low-frequency components of a predetermined frequency f1 or less in the reflected light RL that has passed through the pinhole 35, and cuts off high-frequency components of a predetermined frequency f1 or less. Frequency f1 is, for example, 550 nm.
The laser line filter 62 selectively transmits light of a predetermined frequency f2 in the reflected light RL that has passed through the low-pass filter 61, and blocks light of frequencies other than the frequency f2. The predetermined frequency f2 is, for example, 633 nm.

The detector 70A receives the transmitted light TL and detects a thermal lens signal of the transmitted light TL.
The detector 70A includes a light receiving element 71A, a synchronous detection circuit 72, and an A/D converter 73. The light receiving element 71A, the synchronous detection circuit 72, and the A/D converter 73 are electrically connected.

The light receiving element 71A receives the transmitted light TL and generates an intensity signal corresponding to the intensity of the transmitted light TL. The intensity signal is, for example, the photocurrent. Examples of the light receiving element 71A include a phototube, a photomultiplier tube, a phototransistor utilizing the internal photoelectric effect of a semiconductor, a photodiode, an avalanche photodiode, a photoconductive cell, and an image sensor.

A synchronous detection circuit 72 extracts the thermal lens signal from the intensity signal at a frequency synchronous with the chopping frequency. The synchronous detection circuit 72 is a circuit that demodulates a modulated signal having a carrier such as amplitude modulation or digital modulation. Of the photocurrent generated by the light receiving element 71A receiving the transmitted light TL, a specific component related to the desired transmitted light TL, that is, the same frequency component synchronized with the chopping frequency, which is the modulation frequency of the optical chopper 13, is detected. The synchronous detection circuit 72 is, for example, a lock-in amplifier.

The A/D converter 73 A/D converts the thermal lens signal (output voltage) of the synchronous detection circuit 72 into a digital signal.

The information processing device 80 processes the digital signal value indicating the intensity of the transmitted light TL measured by the synchronous detection circuit 72 as necessary.
The information processing device 80 includes a display unit 81, a reception unit 82, a storage unit 83, and a control unit 84, as shown in FIG.
The information processing device 80 includes a mobile terminal or a stationary terminal. Mobile devices include tablets, smartphones, wearable devices or laptops. Wearable terminals include smart glasses, smart bracelets or smart watches. Stationary terminals include desktops.

The display unit 81 displays information. Display unit 81 includes a display panel. A display panel includes a liquid crystal display, an organic EL display, or an inorganic EL display.

The receiving unit 82 receives instructions from the user. The reception unit 82 includes a touch sensor, keyboard, mouse, or numeric keypad.

The storage unit 83 stores various data. The storage unit 83 includes a main storage device such as a semiconductor memory and an auxiliary storage device such as a semiconductor memory and/or a hard disk drive. Storage unit 83 stores various computer programs executed by control unit 84 . Various computer programs also include firmware and control programs.

The control unit 84 is a hardware circuit including a processor such as a CPU (Central Processing Unit). The control unit 84 controls the display unit 81 , the reception unit 82 , the storage unit 83 , the first light source 11 , the second light source 21 , and the driving unit 52 by executing the control program stored in the storage unit 83 .

(1.1.1) Operation of photothermal conversion analysis device The photothermal conversion analysis device 1A is excited by the first light source unit 10A as shown in FIG. Light EL is emitted as a pulse wave. The excitation light EL is reflected by the dichroic mirror 32 .
The photothermal conversion analyzer 1A emits the probe light PL as a continuous wave from the second light source unit 20 based on the signal input to the reception unit 82 of the information processing device 80 . The probe light PL passes through the dichroic mirror 32 and is aligned on the same optical axis as the excitation light EL reflected by the dichroic mirror 32 .
The excitation light EL and the probe light PL pass through the objective lens 40 and are focused on the opaque sample 2 . The detection unit 70A receives the transmitted light TL obtained by removing the excitation light EL from the reflected light RL reflected by the opaque sample 2 via the thermal lens effect by the optical filter group 60, and detects the thermal lens signal of the transmitted light TL. .

(1.1.2) Optical Paths of Excitation Light and Probe Light The excitation light EL is emitted from the first light source unit 10A, reflected by the first mirror 31, and enters the dichroic mirror 32. FIG. The probe light PL is emitted from the second light source section 20 and enters the dichroic mirror 32 . The excitation light EL and the probe light PL incident on the dichroic mirror 32 are aligned on the same optical axis, emitted from the dichroic mirror 32 , reflected by the second mirror 33 , and incident on the objective lens 40 .
The excitation light EL is focused on the opaque sample 2 by the objective lens 40 . The first sensing component of the opaque sample 2 absorbs the excitation light EL and emits heat by non-radiative relaxation. The heat radiated from the opaque sample 2 is transferred to the air in the vicinity of the opaque sample 2, causing a thermal lens effect. The probe light PL is focused on the opaque sample 2 by the objective lens 40 and reflected on the opaque sample 2 . At this time, the probe light PL is deflected by passing through the area where the thermal lens effect occurs.
The probe light PL reaching the opaque sample 2 is reflected. The reflected light RL including the probe light PL passes through the objective lens 40 again, is reflected by the second mirror 33 , and passes through the dichroic mirror 32 . After that, the reflected light RL is reflected by the prism 22, reflected by the third mirror 34, passes through the pinhole 35 and the optical filter group 60, and is irradiated to the detection section 70A.

(1.2) Initial Deterioration Analysis Method The initial deterioration analysis method according to the first embodiment of the present disclosure includes an analysis area determination process, which will be described later, a calculation process, which will be described later, and a deterioration determination process, which will be described later. The analysis region determination process, calculation process, and deterioration determination process are executed in this order.
According to the initial deterioration analysis method according to the first embodiment, the occurrence of initial deterioration occurring in an opaque sample can be detected with high sensitivity.

(1.2.1) Analysis Region Determination Step In the analysis region determination step, the analysis region on the surface of the opaque sample 2 is determined. The analysis area is, for example, a square area. The analysis area includes a plurality of minute areas. Each of the plurality of minute regions is, for example, a region obtained by regularly dividing the analysis region. Specifically, each of the plurality of minute areas may be one area obtained by dividing the analysis area into 64 areas at equal intervals (8×8). A minute area is, for example, a square area.
When the minute area is a square area, the length of one side of the square area is not particularly limited, and is appropriately selected according to the first detection component and the like. The lower limit of the length of one side of the rectangular region is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 10 μm or more. The upper limit of the length of one side of the rectangular region is preferably less than 100 μm, more preferably 300 μm or less, and still more preferably 1000 μm or less.

(1.2.2) Calculation Step In the calculation step, a first normalized signal and a second normalized signal, which will be described later, are calculated for each of the plurality of minute regions. The calculation step includes a first thermal lens signal detection step, a first reference signal detection step, a first normalized signal calculation step, a second thermal lens signal detection step, a second reference signal detection step, and a second standard and a signal calculation step.

(1.2.2.1) First Thermal Lens Signal Step In the first thermal lens signal step, a first thermal lens signal is detected for each of a plurality of minute regions of the non-aged opaque sample 2 . Specifically, the excitation light EL is incident on the objective lens 40 to generate the first thermal lens effect on the non-aged opaque sample 2, and the probe light PL is incident on the objective lens 40 to produce the non-aged opaque sample 2. The reflected light RL including the probe light PL that is focused on a minute area and reflected by the non-aged opaque sample 2 via the first thermal lens effect is passed through an optical filter group 60 that blocks the excitation light EL. A light TL is emitted, and a first thermal lens signal is detected from the transmitted light TL.
In the first thermal lens signal process, the controller 84 drives the first light source 11 and the second light source 21 . Thereby, the first light source 11 emits the first light L1, and the second light source 21 emits the second light L3. The controller 84 receives the first thermal lens signal from the detector 70A. Upon receiving the first thermal lens signal, the control unit 84 drives the driving unit 52 to move the stage 51 so that the objective lens 40 focuses the probe light PL on another minute area.

(1.2.2.2) First Reference Signal Detecting Step In the first reference signal detecting step, a first reference signal is detected for each of a plurality of minute regions of the non-aged opaque sample 2 . Specifically, in the first reference signal detection step, the excitation light EL is not made to enter the objective lens 40, and the probe light PL is made to enter the objective lens 40 and converge on a small area of the opaque sample 2 that has not aged. The reflected light RL including the probe light PL reflected by the non-aged sample 2 is passed through the optical filter group 60 to emit the transmitted light TL, and the first reference signal is detected from the transmitted light TL.
In the second reference signal detection step, the controller 84 drives the second light source 21 and does not drive the first light source 11 . Accordingly, the first light source 11 does not emit the first light L1, and the second light source 21 emits the second light L3. The control unit 84 receives the first reference signal from the detection unit 70A. Upon receiving the first reference signal, the control unit 84 drives the driving unit 52 to move the stage 51 so that the probe light PL is focused on another minute area by the objective lens 40 .

(1.2.2.3) First Normalized Signal Calculation Step In the first normalized signal calculation step, for each of the plurality of minute regions, the first normalized signal of the corresponding minute region is calculated. The first normalized signal indicates the ratio of the first thermal lens signal to the first reference signal.
In the first normalized signal calculation step, the control section 84 calculates the first normalized signal of the corresponding micro-region for each of the plurality of micro-regions.

(1.2.2.4) Second Thermal Lens Signal Detecting Step In the second thermal lens signal detecting step, a second thermal lens signal is detected for each of a plurality of minute regions of the aged opaque sample 2 . Specifically, the excitation light EL is incident on the objective lens 40 to generate a second thermal lens effect on the aged opaque sample 2, and the probe light PL is incident on the objective lens 40 to generate a minute area of the aged opaque sample 2. , and the reflected light RL including the probe light PL reflected by the aging product of the opaque sample 2 through the second thermal lens effect is passed through the optical filter group 60 to emit the transmitted light TL. to detect the second thermal lens signal.
In the second thermal lens signal process, the controller 84 drives the first light source 11 and the second light source 21 . The controller 84 receives the second thermal lens signal from the detector 70A. Upon receiving the second thermal lens signal, the control unit 84 drives the driving unit 52 to move the stage 51 so that the objective lens 40 focuses the probe light PL on another minute area.

(1.2.2.5) Second Reference Signal Detecting Step In the second reference signal detecting step, a second reference signal is detected for each of the plurality of minute regions of the aged opaque sample 2 . Specifically, in the second reference signal detection step, the excitation light EL is not made to enter the objective lens 40, and the probe light PL is made to enter the objective lens 40 and converge on a minute area of the opaque sample 2 aged. The reflected light RL including the probe light PL reflected by the aging product No. 2 is passed through the optical filter group 60 to emit the transmitted light TL, and the second reference signal is detected from the transmitted light TL.
In the second reference signal detection step, the controller 84 drives the second light source 21 and does not drive the first light source 11 . The control unit 84 receives the second reference signal from the detection unit 70A. Upon receiving the second reference signal, the control unit 84 drives the driving unit 52 to move the stage 51 so that the probe light PL is focused on another minute area by the objective lens 40 .

(1.2.2.6) Second Normalized Signal Calculation Step In the second normalized signal calculation step, for each of the plurality of minute regions, a second normalized signal of the corresponding minute region is calculated. The second normalized signal indicates the ratio of the second thermal lens signal to the second reference signal.
In the second normalized signal calculation step, the control section 84 calculates the second normalized signal of the corresponding micro-region for each of the plurality of micro-regions.

(1.2.3) Degradation Determination Step In the degradation determination step, the following processing is performed based on the first normalized signal and the second normalized signal, and the minute regions of the opaque sample 2 over time are degraded. The control unit determines whether or not.

Step S10: The control section 84 calculates, for each of the plurality of micro-regions, a difference value indicating the absolute value of the difference between the first normalized signal and the second normalized signal of the corresponding micro-region. The process proceeds to step S20.

Step S20: The control unit 84 determines whether the difference value is equal to or greater than the threshold. When the control unit 30 determines that the difference value is equal to or greater than the threshold value (step S20; Yes), it determines that the corresponding minute region of the aging product of the opaque sample 2 has deteriorated. When the control unit 84 determines that the difference value is not equal to or greater than the threshold value (step S20; No), it determines that the corresponding minute region of the aged opaque sample 2 has not deteriorated. The storage unit 83 stores threshold values. The control unit 84 causes the storage unit 83 to store the determination result. The process proceeds to step S30.

Step S30: The control unit 84 causes the display unit 81 to display the determination result determined in step S20. Processing ends.

(1.3) Effects As described with reference to FIGS. 1 to 4, in the first embodiment, the photothermal conversion analyzer 1A includes the first light source unit 10A, the second light source unit 20, the objective lens 40, an optical filter group 60, and a detection section 70A.
As a result, the opaque sample 2 absorbs the irradiated excitation light EL and emits heat. This causes a thermal lens effect in the air near the opaque sample 2 . The probe light PL is focused toward the analysis area of the opaque sample 2 by the objective lens 40 . Therefore, unlike the conventional Mirage method, even if the probe light PL does not pass along the surface of the opaque sample 2, the probe light PL passes through the area where the thermal lens effect occurs. do. The traveling direction of the probe light PL is deflected by the thermal lens effect. At this time, when a slight chemical change occurs in the opaque sample 2, the deflection magnitude of the probe light PL changes. Since the photothermal conversion analyzer 1A includes the optical filter group 60 and the detection unit 70A, it is possible to accurately detect changes in the deflection magnitude of the probe light PL due to the thermal lens effect. As a result, the photothermal conversion analyzer 1A can detect slight chemical changes in the opaque sample 2 with high sensitivity even if the surface of the opaque sample 2 is uneven.

As described with reference to FIGS. 1 to 4, in the first embodiment, the photothermal conversion analyzer 1A has the prism 22 in the second light source section 20. FIG. The prism 22 and the objective lens 40 are adjusted so that the probe light PL is obliquely incident on the surface of the opaque sample 2 .
As a result, the probe light PL condensed by the objective lens 40 toward the analysis area of the opaque sample 2 and reflected by the opaque sample 2 passes through the area where the thermal lens effect occurs. is adjusted to be incident normal to the surface of the opaque sample 2. This makes it easier for the probe light PL to be deflected by the thermal lens effect. As a result, the photothermal conversion analyzer 1A can detect slight chemical changes in the opaque sample 2 with higher sensitivity even if the surface of the opaque sample 2 is uneven.

As described with reference to FIGS. 1 to 4, in the first embodiment, the photothermal conversion analyzer 1A has the first light source section 10A including the first light source 11 and the light chopper 13. FIG. The detection section 70A has a light receiving element 71A and a synchronous detection circuit 72 .
Thus, by using the chopping frequency of the excitation light EL as the reference signal for the synchronous detection circuit 72, the photothermal conversion analyzer 1A can detect weak signals buried in noise. As a result, the photothermal conversion analyzer 1A can detect slight chemical changes in the opaque sample 2 with higher sensitivity even if the surface of the opaque sample 2 is uneven.

As described with reference to FIGS. 1 to 4, in the first embodiment, the objective lens 40 of the photothermal conversion analyzer 1A may be a reflective objective lens 40A.
When the objective lens 40 is the reflective objective lens 40A, the reflective objective lens 40A does not easily absorb light with wavelengths in the visible range or the near-infrared range. Therefore, the photothermal conversion analyzer 1A can detect slight chemical changes in the opaque sample 2 with higher sensitivity even when the opaque sample 2 absorbs excitation light EL in the visible region or the near-infrared region. can.

As described with reference to FIGS. 1 to 4, in the first embodiment, the photothermal conversion analysis device 1A includes the stage 51, the driving section 52, and the control section . The control unit 84 controls the drive unit 52 and the detection unit 70A to acquire thermal lens signals for each of the plurality of analysis regions.
Thereby, the photothermal conversion analyzer 1A can automatically acquire the thermal lens signal of each of the plurality of analysis regions. As a result, the photothermal conversion analyzer 1A can efficiently detect slight chemical changes in the opaque sample 2 . The photothermal conversion analyzer 1A can be used as a microscopic imaging device.

As described with reference to FIGS. 1 to 4, in the first embodiment, the initial deterioration analysis method includes a first thermal lens signal detection step, a second thermal lens signal detection step, and a deterioration determination step. .
As a result, the control unit 84 controls the aging of the opaque sample based on the first thermal lens signal of the analysis region of the non-aged opaque sample 2 and the second thermal lens signal of the analysis region of the aged opaque sample 2 . Determine whether the analysis area of the product is degraded. As a result, the initial deterioration analysis method according to the first embodiment can detect the occurrence of initial deterioration of the opaque sample 2 with high sensitivity.

As described with reference to FIGS. 1 to 4, in the first embodiment, the initial deterioration analysis method includes a first reference signal detection step, a first normalized signal calculation step, and a second reference signal detection step. , and a second normalized signal calculation step.
As a result, the control unit 84 controls the analysis area of the opaque sample 2 based on the first normalized signal of the analysis area of the non-aged opaque sample 2 and the second normalized signal of the analysis area of the aged opaque sample 2. It is determined whether or not the analysis area of the aging product has deteriorated. Because the first normalized signal is the ratio of the first thermal lens signal to the first reference signal, it more clearly indicates the difference in reflectance of the probe light in the analysis region than the first thermal lens signal alone. The second normalized signal likewise more clearly indicates the difference in reflectance of the probe light in the analysis region than the second thermal lens signal alone. As a result, the initial deterioration analysis method according to the first embodiment can detect the occurrence of initial deterioration of the opaque sample 2 with higher sensitivity.

As described with reference to FIGS. 1 to 4, in the first embodiment, the analysis area includes a plurality of minute areas. The control unit 84 determines whether or not each of the plurality of minute regions has deteriorated.
The initial deterioration of the opaque sample 2 tends to occur gradually from weak micro-sites of the opaque sample 2 rather than uniformly from micro-sites. In the first embodiment, the analysis region includes a plurality of minute regions, and the controller 84 determines whether or not each of the plurality of minute regions has deteriorated. As a result, the initial deterioration analysis method of the ninth aspect can detect the occurrence of initial deterioration of the opaque sample 2 with higher sensitivity.

As described with reference to FIGS. 1 to 4, in the first embodiment, in the deterioration determination step, the control unit 84 calculates the difference value of each of the plurality of minute regions, and calculates the difference value of the corresponding minute region. It is determined whether the value is equal to or greater than the threshold, and if the difference value is equal to or greater than the threshold, it is determined that the corresponding minute region of the aging opaque sample 2 has deteriorated, and if the difference value is not equal to or greater than the threshold. , the corresponding minute regions of the aging product of the opaque sample 2 are judged not to have deteriorated.
As described above, the deterioration of the opaque sample 2 over time may be such that the thermal lens signal becomes stronger as the deterioration progresses, or the thermal lens signal becomes weaker as the deterioration progresses. . The first difference value indicates the absolute value of the difference between the first normalized signal of the corresponding minute region of the non-aged opaque sample 2 and the second normalized signal of the corresponding minute region of the aged opaque sample 2. . As a result, in the initial deterioration analysis method according to the first embodiment, for each of the plurality of minute regions of the aging product of the opaque sample 2, the thermal lens signal becomes stronger as the deterioration progresses, and the thermal lens signal becomes stronger as the deterioration progresses. It is possible to accurately detect the occurrence of initial deterioration of the opaque sample 2 regardless of whether it becomes weak or weak.

As described with reference to FIGS. 1 to 4, in the first embodiment, a minute area is a square area with a side length of 1 μm or more and less than 100 μm.
As a result, the initial deterioration analysis method according to the first embodiment can detect the occurrence of initial deterioration of an opaque sample with higher sensitivity.

(2) Second Embodiment A photothermal conversion analyzer 1B according to a second embodiment of the present disclosure will be described with reference to FIG.

The photothermal conversion analyzer 1B mainly differs from the photothermal conversion analyzer 1A (see FIG. 1) in that the detector uses a balanced photodetector instead of the photodetector and the synchronous detection circuit.
As shown in FIG. 5, the photothermal conversion analyzer 1B includes a first light source unit 10A, a second light source unit 20, a first mirror 31, a dichroic mirror 32, a second mirror 33, an objective lens 40, A stage device 50 , a third mirror 34 , a pinhole 35 , an optical filter group 60 , a detection section 70B, and an information processing device 80 are provided.
The photothermal conversion analyzer 1B, like the photothermal conversion analyzer 1A, is a device that analyzes the opaque sample 2 by utilizing the thermal lens effect generated in the air near the opaque sample 2 by heat due to non-radiative relaxation. .

The detection section 70B has a balanced photodetector 71B and an A/D converter 73 . The balanced photodetector 71B is a well-known balanced photodetector and consists of a first photodiode 711 and a second photodiode 712 . The first photodiode 711 receives part of the probe light PL as a reference signal. The second photodiode 712 receives the transmitted light TL. The balanced photodetector 71B cancels common noise between the probe light PL received by the first photodiode 711 and the transmitted light TL received by the second photodiode 712 .

In the second embodiment, the operation of the photothermal conversion analysis device 1B, the optical paths of the excitation light EL and the probe light PL, and the initial deterioration analysis method are the same as in the first embodiment.

As described with reference to FIG. 5, in the second embodiment, a photothermal conversion analysis device 1B includes a first light source unit 10A, a second light source unit 20, an objective lens 40, an optical filter group 60, a detection and a portion 70B.
As a result, the photothermal conversion analyzer 1B can detect slight chemical changes in the opaque sample 2 with higher sensitivity, even if the surface of the opaque sample 2 is uneven, as in the first embodiment.

As described with reference to FIG. 5, in the second embodiment, the initial deterioration analysis method includes a first thermal lens signal detection step, a second thermal lens signal detection step, and a deterioration determination step.
As a result, the initial deterioration analysis method according to the second embodiment can detect the occurrence of initial deterioration of the opaque sample 2 with high sensitivity, as in the first embodiment.

(3) Third Embodiment A photothermal conversion analyzer 1C according to a third embodiment of the present disclosure will be described with reference to FIG.

The photothermal conversion analyzer 1C mainly differs from the photothermal conversion analyzer 1B (see FIG. 6) in that the first light source section does not use an optical chopper.
As shown in FIG. 5, the photothermal conversion analyzer 1B includes a first light source unit 10C, a second light source unit 20, a first mirror 31, a dichroic mirror 32, a second mirror 33, an objective lens 40, A stage device 50 , a third mirror 34 , a pinhole 35 , an optical filter group 60 , a detection section 70B, and an information processing device 80 are provided.
The photothermal conversion analyzer 1C, like the photothermal conversion analyzer 1B, is a device that analyzes the opaque sample 2 by utilizing the thermal lens effect generated in the air near the opaque sample 2 by heat due to non-radiative relaxation. .

The first light source section 10</b>C has a first light source 11 and an optical filter 12 . The first light source 11 is electrically connected to the control section 84 of the information processing device 80 . The control unit 84 controls the timing of driving the first light L1 of the first light source 11 to emit the first light L1 from the first light source 11 as a pulse wave.

In the third embodiment, the operation of the photothermal conversion analysis device 1C, the optical paths of the excitation light EL and the probe light PL, and the initial deterioration analysis method are each the same as in the second embodiment.

As described with reference to FIG. 6, in the third embodiment, the photothermal conversion analysis device 1C includes a first light source unit 10C, a second light source unit 20, an objective lens 40, an optical filter group 60, a detection and a portion 70B.
As a result, the photothermal conversion analyzer 1C can detect slight chemical changes in the opaque sample 2 with higher sensitivity, even if the surface of the opaque sample 2 is uneven, as in the first embodiment.

As described with reference to FIG. 6, in the third embodiment, the initial deterioration analysis method includes a first thermal lens signal detection step, a second thermal lens signal detection step, and a deterioration determination step.
As a result, the initial deterioration analysis method according to the third embodiment can detect the occurrence of initial deterioration of the opaque sample 2 with high sensitivity, as in the second embodiment.

(4) Fourth Embodiment An initial deterioration analysis method according to a fourth embodiment of the present disclosure will be described.

The initial deterioration analysis method according to the fourth embodiment mainly uses a transparent sample instead of an opaque sample and uses a transmissive photothermal conversion analyzer instead of the photothermal conversion analyzer 1A. It is different from the initial deterioration analysis method according to

(4.1) Transmission type photothermal conversion analysis device The transmission type photothermal conversion analysis device used for the initial deterioration analysis method according to the fourth embodiment is a known transmission type photothermal conversion analysis device. As the transmission type photothermal conversion analyzer, the transmission type photothermal conversion analyzers described in Non-Patent Document 1, Non-Patent Document 3, Patent Document 1, International Publication No. 2001/055706, etc. can be used.
A transmission-type photothermal conversion analysis apparatus is an apparatus that analyzes a transparent sample by utilizing the thermal lens effect generated inside the transparent sample by heat due to non-radiative relaxation. More specifically, the transmission type photothermal conversion analyzer converges excitation light and excitation light for generating a thermal lens effect inside the transparent sample through an objective lens on the transparent sample, and a probe that passes through the transparent sample. A transparent sample is analyzed based on the magnitude of the thermal lensing deflection of the light.

The transparent sample used for the initial deterioration analysis method according to the fourth embodiment contains a specific component to be analyzed (hereinafter referred to as "second detection component") and mainly transmits probe light.
The state of the transparent sample is not particularly limited, and may be solid or liquid.
The second detection component is not particularly limited as long as it absorbs excitation light and generates heat by non-radiative relaxation. The number of second detection components may be one, or two or more. The second detection component may be present on at least one of the surface of the transparent sample and the interior of the transparent sample. A transparent sample may be a product. The transparent sample may be, for example, a PVC thin film doped with a dye that forms a complex with a stabilizer (hereinafter referred to as "dyed PVC thin film"). The dye is, for example, dithizone dye.

(4.2) Initial Deterioration Analysis Method An initial deterioration analysis method according to the fourth embodiment of the present disclosure includes an analysis area determination process, which will be described later, a calculation process, which will be described later, and a deterioration determination process, which will be described later. The analysis region determination process, calculation process, and deterioration determination process are executed in this order.
According to the initial deterioration analysis method according to the fourth embodiment, the occurrence of initial deterioration occurring in a transparent sample can be detected with high sensitivity.

(4.2.1) Analysis Region Determination Step In the analysis region determination step, an analysis region on the surface of the transparent sample is determined. The analysis area is the same as that exemplified as the analysis area in the first embodiment.

(4.2.2) Calculation Step In the calculation step, a first normalized signal and a second normalized signal, which will be described later, are calculated for each of the plurality of minute regions. The calculation step includes a first thermal lens signal detection step, a first reference signal detection step, a first normalized signal calculation step, a second thermal lens signal detection step, a second reference signal detection step, and a second standard and a signal calculation step.

(4.2.2.1) First Thermal Lens Signal Step In the first thermal lens signal step, a first thermal lens signal is detected for each of a plurality of minute regions of the non-aged transparent sample. Specifically, the excitation light is incident on the objective lens to generate the first thermal lens effect on the non-aged transparent sample, and the probe light is incident on the objective lens to focus on a minute area of the non-aged transparent sample. , the reflected light including the probe light transmitted through the non-aged transparent sample through the first thermal lens effect is passed through a filter that blocks the excitation light, the transmitted light is emitted, and the transmitted light is converted to the first thermal lens signal to detect

(4.2.2.2) First Reference Signal Detecting Step In the first reference signal detecting step, a first reference signal is detected for each of a plurality of minute regions of the non-aged transparent sample. Specifically, in the first reference signal detection step, the excitation light is not made to enter the objective lens, and the probe light is made to enter the objective lens and converge on a minute area of the non-aged transparent sample. The reflected light including the probe light that passes through is passed through a filter that blocks the excitation light, the transmitted light is emitted, and the first reference signal is detected from the transmitted light.

(4.2.2.3) First Normalized Signal Calculation Step In the first normalized signal calculation step, for each of the plurality of minute regions, the first normalized signal of the corresponding minute region is calculated. The first normalized signal indicates the ratio of the first thermal lens signal to the first reference signal.

(4.2.2.4) Second Thermal Lens Signal Detecting Step In the second thermal lens signal detecting step, a second thermal lens signal is detected for each of a plurality of minute regions of the aged transparent sample. Specifically, the excitation light is incident on the objective lens to generate a second thermal lens effect on the aged transparent sample, the probe light is incident on the objective lens and focused on a minute area of the aged transparent sample, 2. Reflected light including probe light that passes through the aged transparent sample via the thermal lens effect is passed through an optical filter that blocks excitation light, the transmitted light is emitted, and the second thermal lens signal is detected from the transmitted light. do.

(4.2.2.5) Second Reference Signal Detecting Step In the second reference signal detecting step, the second reference signal is detected for each of the plurality of minute regions of the aged transparent sample. Specifically, in the second reference signal detection step, the excitation light is not made to enter the objective lens, and the probe light is made to enter the objective lens and converge on a minute area of the aged transparent sample, and is transmitted through the aged transparent sample. The reflected light including the probe light is passed through an optical filter that blocks the excitation light, the transmitted light is emitted, and the second reference signal is detected from the transmitted light.

(4.2.2.6) Second Normalized Signal Calculation Step In the second normalized signal calculation step, for each of the plurality of minute regions, the second normalized signal of the corresponding minute region is calculated. The second normalized signal indicates the ratio of the second thermal lens signal to the second reference signal.

(4.2.3) Degradation Determination Step In the degradation determination step, the following processing is performed based on the first normalized signal and the second normalized signal, and the minute area of the aged product of the opaque sample 2 is degraded. The control unit determines whether or not.

Step S11: For each of the plurality of micro-regions, the controller calculates a difference value indicating the absolute value of the difference between the first normalized signal and the second normalized signal of the corresponding micro-region. The process proceeds to step S21.

Step S21: The control unit determines whether or not the difference value is equal to or greater than the threshold. When the control unit determines that the difference value is equal to or greater than the threshold value (step S21; Yes), it determines that the corresponding minute region of the aging product of the transparent sample has deteriorated. When the controller determines that the difference value is not equal to or greater than the threshold value (step S21; No), it determines that the corresponding minute region of the aged transparent sample has not deteriorated. Processing ends.

(4.3) Effects In the fourth embodiment, the initial deterioration analysis method includes a first thermal lens signal detection step, a second thermal lens signal detection step, and a deterioration determination step.
Thereby, the control unit analyzes the aged transparent sample based on the first thermal lens signal of the analysis region of the unaged transparent sample and the second thermal lens signal of the analytical region of the aged transparent sample. Determine whether the area is degraded. As a result, the initial deterioration analysis method according to the fourth embodiment can detect the occurrence of initial deterioration of a transparent sample with high sensitivity.

The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In order to facilitate understanding, the drawings schematically show each component mainly, and the thickness, length, number, etc. of each component illustrated are different from the actual ones due to the convenience of drawing. . In addition, the material, shape, dimensions, etc. of each component shown in the above embodiment are examples and are not particularly limited, and various changes are possible within a range that does not substantially deviate from the effects of the present invention. be.

(5) Modification In the photothermal conversion analyzers of the first to third embodiments, the prism 22 and the objective lens 40 are adjusted so that the probe light PL is obliquely incident on the surface of the opaque sample 2. However, the disclosure is not so limited. The prism 22 and the objective lens 40 may be adjusted so that the probe light PL is perpendicularly incident on the surface of the opaque sample 2 .

In the photothermal conversion analysis apparatuses of the first to third embodiments, the stage device 50 includes the drive unit 52, but the present disclosure is not limited to this, and the stage device 50 does not include the drive unit 52. good.

In the photothermal conversion analyzers of the first to third embodiments, the second light source section 20 uses the prism 22 as the incident position adjusting section, but the present disclosure is not limited to this. Instead of the prism 22, a plane mirror, a back surface mirror, or the like may be used.

The photothermal conversion analyzers of the first to third embodiments include a first mirror 31, a dichroic mirror 32, a second mirror 33, a third mirror 34, and a pinhole 35, but the present invention is not limited to this. . Depending on the arrangement of the first light source, the second light source, the objective lens, the optical filter group, and the detector, the photothermal conversion analyzer can be configured as a first mirror 31, a dichroic mirror 32, a second mirror 33, and a third mirror 34. , and at least one of the pinholes 35 may not be provided.
Further, although the photothermal conversion analyzers of the first to third embodiments include the information processing device 80, the present invention is not limited to this, and the photothermal conversion analyzers do not include the information processing device 80. good too.

The initial deterioration analysis method of the first to fourth embodiments includes a first reference signal detection step, a first normalized signal calculation step, a second reference signal detection step, and a second normalized signal calculation step. including, but not limited to, this disclosure. The initial deterioration analysis method of the present disclosure may or may not include the first reference signal detection step, the first normalized signal calculation step, the second reference signal detection step, and the second normalized signal calculation step. . In this case, in the deterioration determination step, the control unit may determine whether or not the analysis region of the aged opaque sample or transparent sample has deteriorated based on the first thermal lens signal and the second thermal lens signal.

In the initial deterioration analysis methods of the first to fourth embodiments, the analysis area includes a plurality of minute areas, but the present invention is not limited to this, and the analysis area may be one. In this case, in the deterioration determination step, the control unit calculates a difference value indicating the absolute value of the difference between the first normalized signal and the second normalized signal of the analysis area of the opaque sample or the transparent sample, and the difference value is the threshold value. If the difference value is greater than or equal to the threshold value, it is determined that the analysis area of the aged opaque sample or transparent sample has deteriorated, and if the difference value is not greater than or equal to the threshold value, the opaque sample Alternatively, it may be judged that the analysis region of the aged transparent sample has not deteriorated.

1A photothermal conversion analyzer 2 opaque sample 10A first light source section 11 first light source 13 optical chopper 20 second light source section 21 second light source 22 prism 40 objective lens 51 stage 52 drive section 60 optical filter group 61 low pass filter 62 laser line filter 70A detection unit 71 light receiving element 72 synchronous detection circuit 80 information processing device 84 control unit EL excitation light PL probe light

Claims (12)

a first light source unit that emits excitation light for generating a thermal lens effect on an opaque sample;
a second light source unit that emits probe light that is reflected by the opaque sample;
an objective lens for concentrating the incident excitation light and the probe light toward an analysis area of the opaque sample and emitting reflected light including the probe light reflected by the opaque sample;
a filter that transmits transmitted light that has blocked the excitation light in the reflected light;
and a detector that receives the transmitted light and detects a thermal lens signal of the transmitted light. The second light source unit has an incident position adjusting unit that adjusts the incident position of the probe light on the objective lens,
2. The photothermal conversion analyzer according to claim 1, wherein said incident position adjusting section and said objective lens are adjusted so that said probe light is obliquely incident on the surface of said opaque sample. The first light source unit
a first light source that emits light;
an optical chopper that intensity-modulates the light with a predetermined chopping frequency to generate the excitation light;
The detection unit is
a light receiving element that receives the transmitted light and generates an intensity signal corresponding to the intensity of the transmitted light;
3. A photothermal conversion analyzer according to claim 1, further comprising a synchronous detection circuit for extracting said thermal lens signal from said intensity signal at a frequency synchronized with said chopping frequency. The photothermal conversion analyzer according to any one of claims 1 to 3, wherein the objective lens is a reflective objective lens. a stage on which the opaque sample is placed;
a driving unit that moves the stage with respect to the objective lens;
and a control unit,
The photothermal conversion according to any one of claims 1 to 4, wherein the control section controls the driving section and the detecting section to acquire the thermal lens signal for each of the plurality of analysis regions. Analysis equipment. a first thermal lens signal detecting step of detecting a first thermal lens signal in an analysis area of the non-aged sample;
a second thermal lens signal detecting step of detecting a second thermal lens signal of the analysis area of the aging product of the sample;
a deterioration determination step in which a control unit determines whether or not the analysis region of the aging product has deteriorated based on the first thermal lens signal and the second thermal lens signal;
In the first thermal lens signal detection step, excitation light is incident on an objective lens to generate a first thermal lens effect on the non-aged product, and probe light is incident on the objective lens to analyze the non-aged product. A first light including the probe light that is focused on a region and transmitted or reflected by the non-aging product via the first thermal lens effect is passed through a filter that cuts off the excitation light so that the first transmitted light is and detecting the first thermal lens signal from the first transmitted light,
In the second thermal lens signal detection step, the excitation light is incident on the objective lens to generate a second thermal lens effect on the aged product, and the probe light is incident on the objective lens to generate the The second light including the probe light that is focused on the analysis area and transmitted or reflected by the aged product via the second thermal lens effect is passed through the filter to emit the second transmitted light, 2. A method of initial deterioration analysis, wherein the second thermal lens signal is detected from transmitted light. a first reference signal detection step of detecting a first reference signal in the analysis region of the non-aged product;
a first normalized signal calculating step of calculating a first normalized signal indicating a ratio of the first thermal lens signal to the first reference signal;
a second reference signal detection step of detecting a second reference signal of the analysis region of the aging product;
a second normalized signal calculating step of calculating a second normalized signal indicating a ratio of the second thermal lens signal to the second reference signal;
In the deterioration determination step, the analysis region of the aging product has deteriorated based on the first normalized signal and the second normalized signal instead of the first thermal lens signal and the second thermal lens signal. The control unit determines whether there is
In the first reference signal detection step, the excitation light is not incident on the objective lens, and the probe light is incident on the objective lens and focused on the analysis region of the non-aged product, passing the third light including the probe light that is transmitted or reflected through the filter to emit third transmitted light, and detecting the first reference signal from the third transmitted light;
In the second reference signal detection step, the excitation light is not incident on the objective lens, and the probe light is incident on the objective lens to be focused on the analysis region of the aged product, and transmitted through or through the aged product. 7. The initial deterioration analysis according to claim 6, wherein the fourth light including the reflected probe light is passed through the filter to emit the fourth transmitted light, and the second reference signal is detected from the fourth transmitted light. Method. In the deterioration determination step,
The control unit
calculating a difference value indicating the absolute value of the difference between the first normalized signal and the second normalized signal in the analysis region;
Determining whether the difference value is greater than or equal to a threshold,
determining that the analysis region of the aging product is degraded when the difference value is equal to or greater than a threshold;
8. The initial deterioration analysis method according to claim 7, wherein when said difference value is not equal to or greater than a threshold value, it is determined that said analysis region of said aging product has not deteriorated. The analysis region includes a plurality of microregions,
In the first thermal lens signal detection step, the first thermal lens signal of each of the plurality of minute regions of the non-aging product is detected;
In the first reference signal detection step, the first reference signal of each of the plurality of minute regions of the non-aging product is detected;
In the first normalized signal calculating step, for each of the plurality of micro-regions, the first normalized signal of the corresponding micro-region is calculated;
In the second thermal lens signal detecting step, the second thermal lens signal of each of the plurality of minute regions of the aged product is detected;
In the second reference signal detection step, the second reference signal of each of the plurality of minute regions of the aging product is detected;
In the second normalized signal calculating step, for each of the plurality of micro-regions, the second normalized signal of the corresponding micro-region is calculated;
In the deterioration determining step, it is determined whether or not each of the plurality of minute regions of the aging product is degraded based on the plurality of first normalized signals and the plurality of second normalized signals. Item 8. The initial deterioration analysis method according to Item 7. In the deterioration determination step,
The control unit
calculating a difference value indicating an absolute value of a difference between the first normalized signal and the second normalized signal of the corresponding micro-region for each of the plurality of micro-regions;
Determining whether the difference value is greater than or equal to a threshold,
if the difference value is equal to or greater than a threshold value, determining that the corresponding minute region of the aged product has deteriorated;
10. The initial deterioration analysis method according to claim 9, wherein when said difference value is not equal to or greater than a threshold value, it is determined that said corresponding minute area of said aging product has not deteriorated. 11. The initial deterioration analysis method according to claim 9 or 10, wherein said minute area is a rectangular area having a side length of 1 [mu]m or more and less than 100 [mu]m. the sample is an opaque sample;
Each of the first light and the third light is reflected against the non-aged product, and each of the second light and the fourth light is reflected against the aged product. 12. The initial deterioration analysis method according to any one of 11.

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