JP5839077B2 - Laser excited fluorescence microscope - Google Patents

Description

  The present invention relates to a laser excitation fluorescence microscope provided with a high-functional dichroic mirror that separates a plurality of types of excitation light and a plurality of types of fluorescence.

  When observing a specimen stained with multiple types of fluorescent dyes with a confocal laser scanning fluorescence microscope, multiple types of laser light with different wavelengths are used as excitation light. A dichroic mirror that separates a plurality of types of fluorescence generated according to the above is used. The wavelength characteristic of this dichroic mirror is characterized in that a plurality of separation wavelengths (rise points from the reflection band to the transmission band) are formed. In the present specification, a dichroic mirror having a plurality of separation wavelengths is referred to as a “high-function dichroic mirror”.

  A solid line in FIG. 20 is a wavelength characteristic curve of the transmittance of the high-functional dichroic mirror introduced in Non-Patent Document 1. As this high-function dichroic mirror, a mirror having a dielectric multilayer film formed on a glass substrate is usually used. In order to separate multiple types of excitation light and multiple types of fluorescence with high efficiency using the dielectric multilayer film, the reflectance of the reflection band increases and the transmittance of the transmission band increases when designing the dielectric multilayer film. What is necessary is to devise so as to suppress the ripple of the wavelength characteristic curve.

Olympus catalog, confocal laser scanning microscope FV1000 FLUOVIEW UIS2

  However, if the characteristics of the dielectric multilayer film are to be strongly controlled, the total film thickness of the dielectric multilayer film tends to increase. When the total film thickness is large, the glass substrate is easily distorted due to the stress of the multilayer film, so that the shape of the laser spot is deteriorated and the spatial resolution of the fluorescent image may be lowered.

Accordingly, an object of the present invention is to provide a laser-excited fluorescence microscope suitable for multiple stained specimens .

One aspect of the laser-excited fluorescence microscope of the present invention is a laser light source unit that emits two types of excitation light that individually excites two types of fluorescent dyes, and a sample that includes the two types of fluorescent dyes. An objective lens that condenses the excitation light, and a dichroic mirror disposed between the laser light source unit and the objective lens, and reflects the two types of excitation light emitted by the laser light source unit to reflect the objective A high-functional dichroic mirror that enters the lens and transmits two types of fluorescence separately generated from the two types of fluorescent dyes included in the specimen according to the two types of excitation light, and the laser light source unit emits the light A mirror that reflects the two types of excitation light and makes the two types of excitation light incident on the dichroic mirror at an incident angle θ smaller than 25 °; and the dichroic mirror An optical scanner that guides the two types of excitation light reflected at − to the objective lens, and causes the two types of fluorescence via the objective lens to enter the dichroic mirror at an incident angle θ smaller than 25 °; And a detector including a detector that spectrally detects the two types of fluorescence transmitted through the dichroic mirror, and the dichroic mirror has a plurality of reflection bands and a plurality of transmission bands.

According to the present invention, a laser-excited fluorescence microscope suitable for a multiple-stained specimen is realized.

FIG. 1 is a configuration diagram of a microscope system. FIG. 2 is a configuration diagram of the spectrum detection unit 600. FIG. 3 is a diagram for explaining the wavelength characteristic curve of the transmittance of the high-functional dichroic mirror 22. FIG. 4 is a diagram showing a configuration of a high-functional dichroic mirror designed under the condition of an incident angle θ = 12 °. FIG. 5 is a continuation of FIG. FIG. 6 is a wavelength characteristic curve of a high-functional dichroic mirror designed under the condition of an incident angle θ = 12 ° (s-polarized component, p-polarized component). FIG. 7 is a wavelength characteristic curve of a high-functional dichroic mirror designed under the condition of an incident angle θ = 12 ° (average of s-polarized component and p-polarized component). FIG. 8 is a diagram showing a configuration of a high-functional dichroic mirror designed under the condition of an incident angle θ = 15 °. FIG. 9 is a continuation of FIG. FIG. 10 is a wavelength characteristic curve of the high-functional dichroic mirror 22 designed under the condition of the incident angle θ = 15 ° (s-polarized component, p-polarized component). FIG. 11 is a wavelength characteristic curve of the high-functional dichroic mirror 22 designed under the condition of the incident angle θ = 15 ° (average of s-polarized component and p-polarized component). FIG. 12 is a diagram showing a configuration of the high-functional dichroic mirror 22 designed under the condition of the incident angle θ = 25 °. FIG. 13 is a continuation of FIG. FIG. 14 is a wavelength characteristic curve of the high-functional dichroic mirror 22 designed under the condition of an incident angle θ = 25 ° (s-polarized component, p-polarized component). FIG. 15 is a wavelength characteristic curve of the high-functional dichroic mirror 22 designed under the condition of an incident angle θ = 25 ° (average of s-polarized component and p-polarized component). FIG. 16 is a diagram (comparative example) showing the configuration of the high-functional dichroic mirror 22 designed under the condition of the incident angle θ = 45 °. FIG. 17 is a continuation of FIG. FIG. 18 is a wavelength characteristic curve (comparative example) of a high-functional dichroic mirror designed under the condition of an incident angle θ = 45 ° (s-polarized component, p-polarized component). FIG. 19 is a wavelength characteristic curve (comparative example) of a high-functional dichroic mirror designed under the condition of an incident angle θ = 45 ° (average of s-polarized component and p-polarized component). FIG. 20 is a wavelength characteristic curve of the transmittance of the high-functional dichroic mirror introduced in Non-Patent Document 1.

  Embodiments of the present invention will be described below. This embodiment is an embodiment of a confocal laser scanning fluorescence microscope system.

  First, the configuration of the microscope system will be described. FIG. 1 is a configuration diagram of a microscope system. As shown in FIG. 1, the microscope system includes a laser unit 10, a confocal unit 100, a microscope main body 110, a detection unit 50, and a control unit (not shown). Among these, the laser unit 10 and the confocal unit 100 are optically coupled by the optical fiber 18, and the confocal unit 100 and the detection unit 50 are optically coupled by the optical fiber 38.

  The microscope body 110 is set with a specimen S that is multiple-stained with a plurality of types of fluorescent dyes. Here, for the sake of simplicity, it is assumed that the number of types of fluorescent dyes used for staining is 2, a first fluorescent dye having an excitation wavelength of 405 nm, and a second fluorescent dye having an excitation wavelength of 488 nm. Incidentally, the fluorescence wavelength of the first fluorescent dye is on the long wavelength side (approximately in the range of 430 nm to 470 nm) of the excitation wavelength, and the fluorescence wavelength of the second fluorescent dye is on the long wavelength side of the excitation wavelength (approximately 510 nm to 610 nm). Range).

  The laser unit 10 includes a laser light source 11 that emits laser light having the same wavelength as the excitation wavelength (405 nm) of the first fluorescent dye, and a laser that emits laser light having the same wavelength as the excitation wavelength (488 nm) of the second fluorescent dye. A light source 12, a total reflection mirror 15, a combiner mirror (dichroic mirror) 16, an AOTF (acousto-optic filter) 14, and a fiber coupler 17 are provided. Incidentally, since the wavelength of the laser light emitted from the laser light source 11 has individual differences, the wavelength of the laser light emitted from the laser light source 12 similarly has a wavelength range of 486 nm to 490 nm. With a range of variations.

  The confocal unit 100 includes a collimating lens 21, a total reflection mirror 22A, a high-functional dichroic mirror 22, an optical scanner (such as a galvano scanner) 23, a pupil projection lens 24, a condenser lens 27, and a pinhole member. 28 and a relay lens 34 are provided. Among these, the high-functional dichroic mirror 22 has a dielectric multilayer film formed as a separation film on a glass substrate.

  The microscope main body 110 includes a condenser lens 25, an objective lens 26, and a stage (not shown) that supports the specimen S. When the objective lens 26 is focused on the sample S, the sample S, the emission end of the optical fiber 18, the pinhole member 28, and the incident end of the optical fiber 38 are optically conjugate.

  The detection unit 50 includes a collimating lens 51, a dichroic mirror 52, emission filters 53 and 56, condenser lenses 54 and 55, and photomultiplier tubes (PMT) 57 and 58.

  In the above microscope system, the laser unit 10, the confocal unit 100, the microscope main body 110, and the detection unit 50 are connected to a control unit (not shown). The control unit is equipped with a control circuit that controls each unit, an arithmetic circuit that executes image processing, and the like. The control unit is connected to an input device and a display device via a computer.

  Next, the operation of the microscope system will be described.

  In the laser unit 10, the laser light emitted from the laser light source 12 passes through the combiner mirror 16, enters the optical fiber 18 through the AOTF 14 and the fiber coupler 17, and travels toward the confocal unit 100. The laser light emitted from the laser light source 11 is reflected by the total reflection mirror 15, then reflected by the combiner mirror 16, and guided to the optical path common to the laser light emitted from the laser light source 12. Note that wavelength selection and light amount adjustment of laser light from the laser unit 10 toward the confocal unit 100 are performed by the AOTF 14.

  In the confocal unit 100, the laser light emitted from the exit end of the optical fiber 18 is converted into a parallel light beam by the collimator lens 21, and enters the total reflection mirror 22A. The laser light incident on the total reflection mirror 22 </ b> A is reflected by the total reflection mirror 22 </ b> A and enters the high-functional dichroic mirror 22.

  The separation wavelength of the high-functional dichroic mirror 22 is set to the long wavelength side of the excitation wavelength (405 nm) of the first fluorescent dye and the long wavelength side of the excitation wavelength (488 nm) of the second fluorescent dye (details will be described later). ). Therefore, the excitation light (wavelength 405 nm) included in the laser light emitted from the laser light source 11 and the excitation light (wavelength 488 nm) included in the laser light emitted from the laser light source 12 are reflected by the high-functional dichroic mirror 22.

  The excitation light reflected by the high-functional dichroic mirror 22 enters the optical scanner 23. The excitation light incident on the optical scanner 23 is sequentially reflected by the two movable mirrors of the optical scanner 23 and then exits the optical scanner 23. The excitation light emitted from the optical scanner 23 goes to the microscope main body 110 through the pupil projection lens 24.

  The excitation light that has entered the microscope main body 110 enters the objective lens 26 via the condenser lens 25. The excitation light incident on the objective lens 26 is collected by the objective lens 26 and forms a laser spot on the specimen S. When the optical scanner 23 is driven in this state, the laser spot scans the sample S two-dimensionally.

  On the laser spot of the sample S, fluorescence is generated. The fluorescence enters the high-functional dichroic mirror 22 through the objective lens 26, the condenser lens 25, the pupil projection lens 24, and the optical scanner 23 while traveling in the reverse direction of the optical path of the excitation light that formed the laser spot. The incident angle of the fluorescence with respect to the high-functional dichroic mirror 22 is the same as the incident angle of the laser light reflected by the total reflection mirror 22A with respect to the high-functional dichroic mirror 22.

  As described above, the separation wavelength of the high-functional dichroic mirror 22 is set to the long wavelength side of the excitation wavelength (405 nm) of the first fluorescent dye and the long wavelength side of the excitation wavelength (488 nm) of the second fluorescent dye. (Details will be described later). Therefore, most of the fluorescence incident on the high function dichroic mirror 22 passes through the high function dichroic mirror 22 and travels toward the condenser lens 27.

  The fluorescence that has entered the condenser lens 27 is condensed toward the pinhole of the pinhole member 28. Of the fluorescent light collected toward the pinhole, extra light incident on the region outside the pinhole is cut by the pinhole member 28, and necessary light incident on the pinhole passes through the pinhole member 28. Then head to the relay lens 34. The fluorescence that has entered the relay lens 34 enters the optical fiber 38 and travels toward the detection unit 50.

  In the detection unit 50, the fluorescence emitted from the emission end of the optical fiber 38 is converted into a parallel light beam by the collimating lens 51 and enters the dichroic mirror 52. The separation wavelength of the dichroic mirror 52 is set to a wavelength between the fluorescence wavelength of the first fluorescent dye (430 nm to 470 nm) and the fluorescence wavelength of the second fluorescent dye (510 nm to 610 nm). Thus, of the fluorescence incident on the detection unit 50, the fluorescence (first fluorescence) generated by the first fluorescent dye is reflected by the dichroic mirror 52, and the fluorescence (second fluorescence) generated by the second fluorescent dye is dichroic mirror 52. Transparent.

  The first fluorescence reflected by the dichroic mirror 52 enters the photomultiplier tube 57 via the emission filter 53 and the condenser lens 54, and the second fluorescence transmitted through the dichroic mirror 52 is emitted by the emission filter 56 and the condenser lens 55. Through the photomultiplier tube 58. Here, each of the emission filters 53 and 56 is an interference filter made of a dielectric multilayer film, and is a filter that selectively transmits only the fluorescence wavelength and blocks the other wavelengths. Therefore, the transmission wavelength band of the emission filter 53 is set to 430 nm to 470 nm, and the transmission wavelength band of the emission filter 56 is set to 510 nm to 610 nm. These filters block the excitation wavelength (405 nm) of the first fluorescent dye and the excitation wavelength (488 nm) of the second fluorescent dye. Therefore, even if the laser light reflected on the laser spot of the sample S is mixed with fluorescence and passes through the same path, it is prevented from entering the photomultiplier tubes 57 and 58 as unnecessary laser light. Each of the photomultiplier tubes 57 and 58 is controlled together with the optical scanner 23 by a control unit (not shown), and generates an electric signal indicating the amount of incident light. Therefore, the electrical signal repeatedly generated by the photomultiplier tube 57 during the above-described two-dimensional scanning shows a fluorescence image by the first fluorescence generated in the sample S, and the photomultiplier during the above-described two-dimensional scanning. The electrical signal repeatedly generated by the tube 58 indicates a fluorescence image due to the second fluorescence generated in the sample S. These fluorescent images are taken into the computer via the control unit and displayed on a display unit or stored in a storage unit (such as a hard disk drive) of the computer.

  In the above microscope system, the spectrum detection unit 600 shown in FIG. 2 can be used instead of the detection unit 50. As shown in FIG. 2, the spectrum detection unit 600 includes a collimating lens 61, a reflective diffraction grating 62, a condensing mirror 63, and a multichannel photomultiplier tube 64. The number of light receiving channels of the photomultiplier tube 64 is 32, for example.

  In the spectrum detection unit 600, the fluorescence emitted from the emission end of the optical fiber 38 is converted into a parallel light beam by the collimator lens 61 and enters the diffraction grating 62. The fluorescence incident on the diffraction grating 62 is reflected in a direction slightly shifted for each wavelength. The fluorescence of each wavelength enters the condenser mirror 63 and is reflected by the condenser mirror 63. The fluorescence of each wavelength reflected by the condensing mirror 63 is condensed on different light receiving channels of the photomultiplier tube 64 and converted into electric signals. The laser light reflected on the laser spot of the sample S is also mixed with the fluorescence and passes through the same path. However, since the wavelength is different from that of the fluorescence, most of the light is condensed outside the light receiving channel of the photomultiplier tube 64. Therefore, it is not converted into an electric signal. The electric signal of each channel repeatedly generated by the photomultiplier tube 64 during the above-described two-dimensional scanning period indicates a fluorescence spectrum image of the sample S. This fluorescence spectrum image is taken into a computer via the control unit and displayed on a display device or stored in a storage unit (hard disk drive or the like) of the computer.

  The computer that captures the fluorescence spectrum image is based on the emission spectrum data of the first fluorescent dye released by the reagent manufacturer and the emission spectrum data of the second fluorescent dye released by the reagent manufacturer. Thus, the fluorescence image by the first fluorescence and the fluorescence image by the second fluorescence can be separated (unmixed).

  Next, the high function dichroic mirror 22 will be described.

  As shown in FIG. 1, the posture of the high-functional dichroic mirror 22 is set so that the incident angle θ of laser light and fluorescence with respect to the high-functional dichroic mirror 22 is smaller than 45 °. A total reflection mirror 22 </ b> A disposed in front of the high function dichroic mirror 22 is an optical path bending mirror disposed to fold the incident optical path of the high function dichroic mirror 22.

  Thus, when the incident angle θ is smaller than 45 °, the wavelength characteristic of the reflection / transmittance of the high-functional dichroic mirror 22 becomes less dependent on the polarization direction of the incident light. As a result, it becomes easy to suppress the total film thickness of the dielectric multilayer film necessary to obtain a desired wavelength characteristic. Actually, when the incident angle θ is smaller than 45 °, the total film thickness of the dielectric multilayer film of the high-functional dichroic mirror 22 is suppressed to less than 19.3193 μm.

  Further, since the dielectric multilayer film is thinned, the film stress is weakened and the flatness of the high-functional dichroic mirror 22 is maintained, so that the shape of the laser spot is also kept good. The resolution is kept high. Further, since the dielectric multilayer film is thinned and the number of layers is reduced, the manufacturing cost of the high-functional dichroic mirror 22 can be suppressed.

  Incidentally, the smaller the incident angle θ, the easier the dielectric multilayer film becomes thinner. For example, if the incident angle θ is smaller than 25 °, the total film thickness is suppressed to less than 13.433647 μm, and if the incident angle θ is smaller than 15 °, the total film thickness is suppressed to less than 10.27728 μm. If the incident angle θ is set to 12 °, the total film thickness can be suppressed to 9.42428 μm.

  However, it is desirable that the incident angle θ is not too small, and it is desirable to ensure 10 ° at the minimum. This is because when the incident angle θ is 10 ° or less, a large distance from the high-functional dichroic mirror 22 to the optical element (the total reflection mirror 22A or the optical scanner 23) around the high-function dichroic mirror 22 must be secured so that necessary light rays are not kicked. This is because the confocal unit 100 becomes larger.

  Therefore, in the present embodiment, the incident angle θ is in the range of 0 ° <θ <45 °, preferably in the range of 10 ° <θ <25 °, more preferably in the range of 10 ° <θ <15 ° (for example, It shall be set to about 12 °.

  In the present embodiment, the wavelength characteristic is controlled as follows using the fact that the wavelength characteristic of the high-functional dichroic mirror 22 is easily controlled.

  Next, conditions that the wavelength characteristics of the high-functional dichroic mirror 22 satisfy will be described. FIG. 3 is a diagram for explaining the wavelength characteristic curve of the transmittance of the high-functional dichroic mirror 22.

  As shown in FIG. 3, the wavelength characteristic curve of the high-functional dichroic mirror 22 includes a first reflection band 301, a first transmission band 401, a second reflection band 302, and a second transmission band in order from the short wavelength side. 402 are lined up.

  Of these, the first reflection band 301 covers the excitation wavelength of one of the two types of fluorescent dyes, and the second reflection band 302 covers the other excitation wavelength.

  The first transmission band 401 covers the fluorescence wavelength of one of the two fluorescent dyes, and the second transmission band 402 covers the fluorescence wavelength of the other fluorescent dye.

  Therefore, the boundary wavelength between the first reflection band 301 and the first transmission band 401 corresponds to one separation wavelength of the high-functional dichroic mirror 22, and the boundary between the second reflection band 302 and the second transmission band 402. The wavelength corresponds to the other separation wavelength of the high-functional dichroic mirror 22.

Here, the reflectance of the first reflection band 301, the reflectance of the second reflection band 302, the transmittance of the first transmission band 401, and the transmittance of the second transmission band 402 are each 95% or more. , wavelength width _{T 1} of the first transmitting band 401, a wavelength width _{T 2} of the second transmitting band 402 is respectively 25nm or more.

  Therefore, according to this highly functional dichroic mirror 22, the excitation light of each of the two types of fluorescent dyes can be efficiently introduced into the microscope main body 110, and each of the two types of fluorescence generated in the specimen S can be detected by the detection unit. 50 (or spectrum detection unit 600) can be efficiently introduced. Therefore, the microscope system of the present embodiment can detect each of the two types of fluorescent images with high sensitivity.

In order to further increase the detection sensitivity, the reflectance of the first reflection band 301 represents 98% or more values for over 90 percent of its wavelength width R _1, the reflectance of the second reflection band 302 , the indicates the wavelength width of 98% or more of the values over 90% of _{R 2,} the transmittance of the first transmitting band 401 indicates the 98% value over 90% of the wavelength width _{T 1} , the transmittance of the second transmitting band 402, it is desirable to show a 98% or more values for over 90 percent of its wavelength width T _2.

Also, the rising width _{A 1} from the first reflecting band 301 to the first transmitting band 401 is 6nm or less, the rising width _{A 2} from the second reflecting band 302 to the second transmitting band 402 is 6nm or less. That is, the rise from the first reflection band 301 to the first transmission band 401 and the rise from the second reflection band 302 to the second transmission band 402 are steep.

  Therefore, even if one or both Stokes shifts of the two types of fluorescent dyes are short, the detection sensitivity of the two types of fluorescent images does not decrease.

  Further, the gap B between the first transmission band 401 and the second transmission band 402 is suppressed to 20 nm or less. Further, as described above, since the transmittance of each of the first transmission band 401 and the second transmission band 402 is as high as 95% or more, a ripple is generated in each of the first transmission band 401 and the second transmission band 402. It can be regarded as not.

  Accordingly, the fluorescence spectrum image detected by the spectrum detection unit 600 (FIG. 2) reflects the spectrum of the fluorescence generated in the specimen S almost without any loss. As a result, the aforementioned unmixing is performed with high accuracy.

  Further, since the reflectivity of each of the first reflection band 301 and the second reflection band 302 is as high as 95% or more, the possibility of unnecessary laser light entering the detection unit 50 (or the spectrum detection unit 600) is low. .

  Therefore, the detection unit 50 (or spectrum detection unit 600) can detect a fluorescence image (or fluorescence spectrum image) with a high S / N ratio. In particular, in the spectrum detection unit 600, an interference filter made of a dielectric multilayer film is the most effective measure for preventing unwanted laser light from entering the multichannel photomultiplier tube 64. Can not be used, and it is difficult to detect a fluorescence spectrum image with a high S / N ratio.

  Next, an embodiment of the high function dichroic mirror 22 will be described.

4 and 5 are diagrams showing the configuration of the high-functional dichroic mirror 22 designed under the condition of the incident angle θ = 12 °. The configuration is such that Nb ₂ O ₅ dielectric films and SiO ₂ dielectric films are alternately formed on a quartz glass substrate. 5 is a continuation of FIG. As shown in FIGS. 4 and 5, the total thickness of the dielectric multilayer film is suppressed to 9.42428 μm under the condition of the incident angle θ = 12 °.

  6 and 7 are wavelength characteristic curves of the high-functional dichroic mirror 22 designed under the condition of the incident angle θ = 12 °. In FIG. 6, the characteristic for the s-polarized component and the characteristic for the p-polarized component are drawn separately, and in FIG. 7, the average of the characteristic for the s-polarized component and the characteristic for the p-polarized component is drawn. As shown in FIG. 6, under the condition of θ = 12 °, the variation between the characteristic for the p-polarized component and the characteristic for the s-polarized component is small, so the shape of the wavelength characteristic curve is good as shown in FIG. The “good shape” as used herein means that the reflectance of the reflection band is high, the transmittance of the transmission band is high, the rise from the reflection band to the transmission band is steep, and the gap between the transmission bands is narrow, It refers to a shape with little ripple.

8 and 9 are diagrams showing the configuration of the high-functional dichroic mirror 22 designed under the condition of the incident angle θ = 15 °. The configuration is such that Nb ₂ O ₅ dielectric films and SiO ₂ dielectric films are alternately formed on a quartz glass substrate. FIG. 9 is a continuation of FIG. As shown in FIGS. 8 and 9, the total thickness of the dielectric multilayer film is suppressed to 10.27728 μm under the condition of the incident angle θ = 15 °.

  10 and 11 are wavelength characteristic curves of the high-functional dichroic mirror 22 designed under the condition of the incident angle θ = 15 °. In FIG. 10, the characteristic for the s-polarized component and the characteristic for the p-polarized component are drawn separately, and in FIG. 11, the average of the characteristic for the s-polarized component and the characteristic for the p-polarized component is drawn. As shown in FIG. 10, under the condition of θ = 15 °, the variation between the characteristic for the p-polarized component and the characteristic for the s-polarized component is small, so the wavelength is not as great as when θ = 12 °. The shape of the characteristic curve is good.

12 and 13 are diagrams showing the configuration of the high-functional dichroic mirror 22 designed under the condition of the incident angle θ = 25 °. The configuration is such that Nb ₂ O ₅ dielectric films and SiO ₂ dielectric films are alternately formed on a quartz glass substrate. FIG. 13 is a continuation of FIG. As shown in FIGS. 12 and 13, the total thickness of the dielectric multilayer film is suppressed to 13.43647 μm under the condition of the incident angle θ = 25 °.

  14 and 15 are wavelength characteristic curves of the high-functional dichroic mirror 22 designed under the condition of the incident angle θ = 25 °. In FIG. 14, the characteristic for the s-polarized component and the characteristic for the p-polarized component are drawn separately, and in FIG. 15, the average of the characteristic for the s-polarized component and the characteristic for the p-polarized component is drawn. As shown in FIG. 14, under the condition of θ = 25 °, the variation between the characteristic for the p-polarized component and the characteristic for the s-polarized component is small, so the wavelength is not as great as when θ = 15 °. The shape of the characteristic curve is good.

FIGS. 16 and 17 are diagrams (comparative examples) showing the configuration of a high-functional dichroic mirror designed under the condition of an incident angle θ = 45 °. The configuration is such that Nb ₂ O ₅ dielectric films and SiO ₂ dielectric films are alternately formed on a quartz glass substrate. FIG. 17 is a continuation of FIG. As shown in FIGS. 16 and 17, the total thickness of the dielectric multilayer film is 19.3193 μm under the condition of the incident angle θ = 45 °.

  18 and 19 are wavelength characteristic curves (comparative examples) of a high-functional dichroic mirror designed under the condition of an incident angle θ = 45 °. In FIG. 18, the characteristic for the s-polarized component and the characteristic for the p-polarized component are drawn separately, and in FIG. 19, the average of the characteristic for the s-polarized component and the characteristic for the p-polarized component is drawn. As shown in FIG. 18, under the condition of θ = 45 °, there is a large variation between the characteristic for the p-polarized component and the characteristic for the s-polarized component. Therefore, as shown in FIG.

  4 to 19, it has been found that the smaller the incident angle θ, the thinner the dielectric multilayer film and the better the shape of the wavelength characteristic curve. Therefore, both the prevention of distortion of the high-functional dichroic mirror 22 and the enhancement of the performance of the high-functional dichroic mirror 22 can be achieved at the same time by simply reducing the incident angle θ to the high-functional dichroic mirror 22 to less than 45 °. it is obvious.

(Other)
In the microscope system of the present embodiment, the laser unit 10 and the high-functional dichroic shown in FIG. Each of the mirror 22 and the dichroic mirror 52 is preferably exchangeable. In this case, for example, the confocal unit 100 is mounted with a turret (wheel-shaped exchange device) on which a plurality of types of high-functional dichroic mirrors having different combinations of separation wavelengths are mounted.

  Incidentally, in the exchange device, the diameter of the wheel is increased by the number of the dichroic mirrors, and the size of the switching device is usually increased. However, the incident angle θ with respect to the dichroic mirror is smaller than 45 ° as in the microscope system of the present embodiment. In this case, since the area of the dichroic mirror can be reduced, the exchange device can be reduced in size accordingly.

  Further, in the present embodiment, it is assumed that the number of types of fluorescent dyes that stain the specimen S is 2, but the number may be expanded to 3 or more. In this case, the number of types of laser light that can be emitted by the laser unit 10 is set to 3 or more, the number of separation wavelengths of the high-functional dichroic mirror 22 is also set to 3 or more, and the number of fluorescent images that can be detected by the detection unit 50 (Or the number of fluorescent images that can be unmixed by the computer) is also set to 3 or more. As described above, even when the number of types of fluorescent dyes is 3 or more, the same effect as that of the above-described embodiment can be obtained only by making the incident angle θ with respect to the high-functional dichroic mirror 22 smaller than 45 °.

  DESCRIPTION OF SYMBOLS 10 ... Laser unit, 100 ... Confocal unit, 110 ... Microscope, 50 ... Detection unit, 18 ... Optical fiber, 38 ... Optical fiber, 11 ... Laser light source, 12 ... Laser light source, 15 ... Total reflection mirror, 16 ... Combiner mirror (Dichroic mirror), 14 ... AOTF (acousto-optic filter), 17 ... fiber coupler

Claims (7)

A laser light source unit that emits two types of excitation light for individually exciting two types of fluorescent dyes, an objective lens that focuses the two types of excitation light onto a specimen containing the two types of fluorescent dyes, and the laser A dichroic mirror disposed between a light source unit and the objective lens ,
The two types of excitation light emitted from the laser light source unit are reflected and incident on the objective lens, and are generated individually from the two types of fluorescent dyes included in the specimen according to the two types of excitation light. High-function dichroic mirror that transmits two types of fluorescence;
A mirror that reflects the two types of excitation light emitted by the laser light source unit and causes the two types of excitation light to enter the dichroic mirror at an incident angle θ smaller than 25 °;
An optical scanner that guides the two types of excitation light reflected by the dichroic mirror to the objective lens and causes the two types of fluorescence via the objective lens to enter the dichroic mirror at an incident angle θ smaller than 25 °. When,
And a detection unit including a detector for detecting spectrally the two fluorescence transmitted through the dichroic mirror,
The laser-excited fluorescence microscope , wherein the dichroic mirror has a plurality of reflection bands and a plurality of transmission bands .   In the laser excitation fluorescence microscope of Claim 1,
  An unmixing unit that unmixes the fluorescence spectrum data generated by the detection unit into fluorescence spectrum data corresponding to one of the two types of fluorescent dyes and fluorescence spectrum data corresponding to the other;
  A laser-excited fluorescence microscope characterized by that.   In the laser excitation fluorescence microscope according to claim 1 or 2,
The wavelength characteristic curve of reflection / transmittance of the dichroic mirror is
  The reflectance of each of the plurality of reflection bands is 95% or more,
  The transmittance of each of the plurality of transmission bands is 95% or more,
  Each of the wavelength widths of the plurality of transmission bands is 25 nm or more,
  The rising width from the reflection band corresponding to one excitation wavelength of the two kinds of fluorescent dyes to the transmission band corresponding to one fluorescence wavelength of the two kinds of fluorescent dyes, and the other excitation wavelength of the two kinds of fluorescent dyes Each of the rising widths from the reflection band corresponding to 1 to the transmission band corresponding to the other fluorescence wavelength of the two types of fluorescent dyes is 6 nm or less.
A laser-excited fluorescence microscope characterized by that. In the laser excitation fluorescence microscope as described in any one of Claims 1-3 ,
An incident angle θ of the excitation light and the fluorescence with respect to the dichroic mirror satisfies an expression of 10 ° <θ <25 °. In the laser excitation fluorescence microscope of Claim 4 ,
An incident angle θ of the excitation light and the fluorescence with respect to the dichroic mirror satisfies an expression of 10 ° <θ <15 °. In the laser excitation fluorescence microscope of Claim 5 ,
The incident angle θ of the excitation light and the fluorescence to the dichroic mirror is
A laser-excited fluorescence microscope characterized by being 12 °. In the laser excitation fluorescence microscope as described in any one of Claims 1-6 ,
The separation membrane of the dichroic mirror is
A laser-excited fluorescence microscope comprising a dielectric multilayer film.

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