CN106500591A - A kind of integrated form multiband Michelson's interferometer - Google Patents

Abstract

The invention provides an integrated multi-band Michelson interferometer. Including photodetector, light source, collimator, dichroic prism and its adjustment system, fixed reflector, cuvette and its fixed system, movable reflector system, optical path compensator and signal processing unit, said photodetector is 8-band photodetector, the light source is a wide-spectrum light source, and the broadband light source outputs multi-band continuous light waves. The light waves of each band pass through the Michelson interferometer to form a set of white light interference patterns, and pass through the independent 8-band photoelectric The detector and the signal processing unit realize the independent detection of the 8-band white light interference signals at the same time. The invention utilizes a wide-spectrum light source, a beam splitting prism and its adjustment system, and a multi-band photodetector to construct an integrated technical scheme of a multi-band Michelson interferometer. It can be used for the measurement of optical properties such as refraction and dispersion of transparent media, especially suitable for the measurement and identification of transparent liquids.

Description

An integrated multi-band Michelson interferometer

technical field

The invention relates to an integrated multi-band Michelson interferometer.

Background technique

The well-known Michelson interferometer is a precision optical instrument designed and manufactured by American experimental physicists Michelson and Morley for the study of "ether" drift. It uses the sub-amplitude method to generate double beams to achieve interference. By adjusting the interferometer, it is possible to generate equal-thickness interference fringes, and it is also possible to generate equal-tilt interference fringes.

Using the well-known principle of Michelson interferometer, researchers have developed a variety of special interferometers. Among them, the Michelson interferometer based on white light can use a low-coherence light source with a wide spectrum and a short coherence length, and use the interference fringes generated by interference to perform absolute measurements of parameters such as optical path and optical dispersion. It has strong anti-interference ability and simple structure. , low cost and other advantages.

The light source of the known white light Michelson interferometer is generally monochromatic light, and the main technologies related to this, such as optical path matching, signal modulation and demodulation, etc., have been matured. Various sensors designed based on the well-known Michelson interferometer have high precision and high sensitivity when measuring a single target.

However, under the technical background of sensor function integration, intelligence, and networking, the application of the traditional and well-known Michelson interferometer is limited due to the single measurement target. In engineering practice, using a set of sensing systems to measure multiple targets simultaneously, or to measure multiple bands of the same measurement target, is an important technical means to obtain richer information and comprehensively evaluate the measured object. Since the known white light Michelson interferometer usually uses a monochromatic light source, when measuring the refraction and dispersion characteristics of a medium, only a set of specific wavelengths of refraction indices can be obtained in one measurement. In actual production, the acquisition of the refractive index and dispersion characteristics of some doped transparent media requires more abundant measurement information to obtain accurate measurement results, which cannot be accomplished by a single measurement of a monochromatic light Michelson interferometer. .

Contents of the invention

The purpose of the present invention is to provide an integrated multi-band Michelson interferometer capable of realizing multi-dimensional evaluation of optical properties such as refraction and dispersion of detected substances.

The object of the present invention is achieved like this: comprise photodetector, light source, collimator, dichroic prism and adjustment system thereof, fixed reflector, cuvette and fixation system thereof, movable reflector system, optical path compensator and signal Processing unit, the photodetector is an 8-band photodetector, the light source is a wide-spectrum light source, an 8-band photodetector, a wide-spectrum light source, a collimator, a beam splitting prism and its adjustment system, a fixed reflector, a ratio The color dish and its fixed system, moving mirror system, optical path compensator and signal processing unit are integrated on the same optical circuit substrate to form 8 Michelson interferometers working in different bands. The wide-spectrum light source outputs multi-band continuous light waves. The light waves of each band pass through the Michelson interferometer to form a set of white light interference patterns, and realize the independent detection of the 8 band white light interference signals at the same time through the independent 8-band photodetectors and signal processing units.

The present invention may also include:

1. The beam-splitting prism and its adjustment system are composed of a beam-splitting prism, a fixed base of the beam-splitting prism, and a fixed base angle adjustment frame. The internal and external outlines of the fixed base angle adjustment frame are square. There are 4 through small holes on the top view surface, the center of each small hole is located at the symmetrical center of each side of the adjustment frame, and there are 2 through holes on the front and rear elevations of the fixed base angle adjustment frame, the same The two wire holes on the facade are symmetrically distributed on both sides of the small hole on the corresponding side surface of the facade, and the wire holes on the front and rear facades are collinear.

2. The top-view surface of the fixed base of the beam-splitting prism is square, and there is a countersunk head penetrating through the center of the top-view surface; The center of the surface, and the four sides of the square of the top view projection surface of the prism are parallel to the square four sides of the top view surface of the fixed base.

3. It also includes a polarizer for controlling the polarization state of each band of light waves entering the beam splitting prism and its adjustment system, and an analyzer for keeping the multi-band light waves entering the 8-band photodetector in exactly the same polarization state.

The present invention provides an integrated technical solution of a multi-band Michelson interferometer constructed by using a wide-spectrum light source, a beam splitting prism and its adjustment system, and a multi-band photodetector, and its purpose is to overcome the single-band Michelson interference in the prior art The measurement target brought by the instrument is single and cannot comprehensively evaluate the nature of the detected target.

Main features of the present invention are reflected in:

1. Integrate 8 Michelson interferometers working in different bands on the same optical circuit substrate, which consists of 8-band photodetectors, optical circuit substrates, wide-spectrum light sources, collimators, beam splitters and their adjustment systems, fixed reflectors Mirror, polarizer, analyzer, cuvette and its fixing system, moving mirror system, optical path compensator, and signal processing unit.

The benefit of this approach is that each light source in a specific wavelength band in the wide-spectrum light source will be connected with the collimator, beam splitter and its adjustment system, fixed mirror, polarizer, analyzer, and colorimeter on the optical path substrate. The dish and its fixing system, the moving mirror system, the optical path compensator, and the detection unit used in the 8-band photodetector for detecting the light waves emitted by the light source of the aforementioned specific band constitute a Michelson interferometer.

The benefit of this approach is also that: the 8-band photodetector, collimator, beam splitter and its adjustment system, fixed mirror, polarizer, analyzer, cuvette and its fixing system, optical path compensator All are installed on the same optical circuit substrate, which not only technically realizes the integration of 8 different waveband Michelson interferometers, but also increases the overall stability of the system.

2. The wide-spectrum light source outputs multi-band continuous light waves. The light waves of each band pass through the Michelson interferometer to form a set of white light interference patterns. Through the independent 8-band photodetectors and signal processing units, 8 bands are simultaneously realized. The white light interference signals are independently detected.

The benefit of this approach is that since the 8-band photodetector can realize the individual detection of each band or the detection of several bands at the same time, according to the technical measurement needs and the properties of the measurement target, through the signal processing unit, the 8-band The working mode of the photodetector is optimized.

Since the white light of the 8 bands is in the visible light band, it is easy to obtain a wide-spectrum light source, and ordinary halogen lamps and natural light can be used as working light sources.

3. The beam-splitting prism and its adjustment system are composed of three parts: the beam-splitting prism, the fixed base of the beam-splitting prism, and the angle adjustment frame of the fixed base.

The internal and external outlines of the fixed base angle adjustment frame are square; there are 4 through small holes in the top view of the fixed base angle adjustment frame, and the center of each small hole is located at the symmetrical center of each side of the adjustment frame ; On the front view surface and the rear view surface of this fixed base angle adjustment frame, there are respectively two through thread holes, and the two thread holes on the same view surface are symmetrically distributed on the side surface corresponding to the view surface. On both sides of the small hole, the silk holes on the front and rear viewing planes are collinear.

On the top view surface of the angle adjustment frame of the aforementioned fixed base, there are four small holes through which the function is to fix the adjustment frame on the optical path substrate. In the 4 thread holes opened on the angle adjustment frame of the fixed base, after screwing the top wires respectively, each top wire supports the corresponding side elevation of the beam splitting prism and the fixed base of the adjustment system thereof. In this way, when the top wire is screwed in or out, the whole composed of the beam splitting prism and the beam splitting prism fixing base can be controlled and finally fixed, so as to realize the angle adjustment of the beam splitting prism.

In the beam-splitting prism and its adjustment system, the top view surface of the beam-splitter prism fixed base is a square, and a countersunk head penetrates a small hole in the center of the top-view surface; The prism is fixed at the center of the top view surface of the base, and the square four sides of the top view projection surface of the prism are parallel to the square four sides of the top view surface of the fixed base.

There is a countersunk head through the small hole in the center of the fixed base of the beam splitting prism. The benefit is that: because the white light Michelson interferometer has strict requirements on the optical path matching, the angle has a direct impact on the optical path matching. On the base, the whole composed of the beam splitting prism and the fixing base of the beam splitting prism can be installed on the optical circuit substrate through the small hole of the countersunk head, so that the whole can be rotated in the plane centered on the small hole of the countersunk head, which can be regarded as the beam splitting prism. Angle adjustment provides convenience.

The integrated multi-band Michelson interferometer of the invention can be used for measuring the optical properties and dispersion properties of various transparent media and materials. It is especially suitable for the measurement and identification of transparent liquids, such as: alcohol, sugar drinks; various edible vegetable oils; various transparent medical injection liquids, etc.

Compared with the prior art, the present invention integrates white light Michelson interferometers of at least 8 bands on the same optical circuit substrate by adopting the technical means of wide-spectrum light source and multi-band photodetector, and manufactures a Integrated multi-band Michelson interferometry system. This interferometer can be used to observe the refractive index and dispersion characteristics of matter. Since the interferometer can work in 8 bands of natural light, 8 characteristic spectra can be obtained simultaneously for the observation of the same substance. The comprehensive analysis of these spectra can make a multi-dimensional evaluation of the refraction and dispersion characteristics of the detected substance, thereby improving the accuracy of the detection and identification of the optical properties of the substance.

Description of drawings

Figure 1 is a schematic diagram of the three-dimensional structure of the multi-band integrated Michelson interferometer system.

Fig. 2 is a schematic diagram of the multi-band integrated Michelson interferometer in the present invention.

Fig. 3 is a schematic top view of a beam splitting prism and its adjustment system.

Fig. 4 is a front view (or rear view) schematic diagram of a dichroic prism and its adjustment system.

Fig. 5 is a schematic front view of the fixing base of the dichroic prism.

Fig. 6 is a schematic diagram of the structure of the moving mirror system.

Fig. 7 is a schematic diagram of an embodiment using a halogen lamp as a multi-band light source.

detailed description

The following examples describe the present invention in more detail.

1 and 2, the multi-band integrated Michelson interferometer system of the present invention consists of an 8-band photodetector 1, a wide-spectrum light source 3, a collimator 4, a beam splitter and its adjustment system 5, a fixed reflector 6, A polarizer 7, an analyzer 8, a cuvette and its fixing system 9, a moving mirror system 10, an optical path compensator 11, and a signal processing unit 12. Installed on the same optical path substrate 2.

In conjunction with Fig. 3, the beam splitting prism and its adjustment system 5 are composed of a beam splitting prism 13, a beam splitting prism fixed base 14, a fixed base angle adjustment frame 15, a top wire 16, a top wire 17, a top wire 18, and a top wire 19; The adjusting frame 15 is provided with through holes, which are respectively a through hole 20 , a through hole 21 , a through hole 22 and a through hole 23 .

Referring to FIG. 4 , the dichroic prism and its adjustment system 5 are composed of a dichroic prism 13 , a fixed base 14 for the dichroic prism, and an angle adjustment frame 15 for the fixed base. Have thread holes 24, 25 on the front view surface of the fixed base angle adjustment frame 15; thread holes 26, 27 on the rear view surface. The front view (or rear view) projection planes of the through wire holes 24, 26 are coincident; the front view (or rear view) projection planes of the through wire holes 25, 27 are coincident.

Referring to FIG. 5 , there is a countersunk through hole 28 at the center of the dichroic prism fixing base 14 .

Referring to FIG. 6 , the moving mirror system 10 is composed of a micron-scale displacement scanning stage 29 , a micron-scale displacement scanning stage control unit 30 , and a mirror 31 .

Referring to FIG. 7 , in the embodiment using a halogen lamp as a multi-band light source, a halogen lamp is selected as a wide-spectrum light source including all eight detection bands. The composition of this embodiment includes: a photodetector 1 with 8 bands, an optical path substrate 2, a halogen lamp 3, a collimation system 4, a beam splitting prism and its adjustment system 5, a fixed mirror system 6, a polarizer 7, a detector A polarizer 8 , a cuvette and its fixing system 9 , a moving mirror system 10 , an optical path compensator 11 , and a signal processing unit 12 .

It is a technical scheme used by the present invention to obtain the refraction and dispersion characteristics of a certain transparent liquid. According to the embodiment shown in Figure 7, its spatial light path is as follows:

The multi-band light waves emitted by the halogen lamp 3 pass through the collimation system 4 , enter the beam splitter prism and its adjustment system 5 , and then split into two beams. The reflected light beam is vertically incident on the fixed mirror system 6 and reflected by the mirror, then enters the beam splitting prism and its adjustment system 5 again, and then transmits through the beam splitting prism and its adjustment system 5, then arrives at the 8-band photodetector 1 wherein the transmitted light beam is vertically incident on the moving mirror system 10, and after being reflected by the mirror, enters the beam splitting prism and its adjustment system 5 again, and after being reflected by the beam splitting prism and its adjustment system 5, arrives at the 8-band photodetector 1.

The eight characteristic wavebands selected are all located in the visible light waveband, and their respective center wavelengths are: 428nm, 460nm, 490nm, 515nm, 557nm, 615nm, 660nm, 695nm.

According to needs, the polarizer 7 that can be placed in the optical path, the purpose is to control the polarization state of each band light wave that enters the beam splitting prism and its adjustment system 5; The multi-band light waves of the device, especially the light waves of the same band are in the same polarization state, thereby improving the coherent contrast of the optical signal.

According to the embodiment shown in Figure 7, its optical path matching is realized as follows:

In the moving mirror system 10 , the mirror 31 is installed on the micron displacement scanning stage 29 . When the optical path of the signal arm in the integrated multi-band Michelson interferometer described in the present invention changes, the optical path matching is realized by controlling the forward and backward movement of the mirror through the micron-level displacement scanning stage control unit 30 .

According to the embodiment shown in Figure 7, the detection of the refraction and dispersion characteristics of a certain transparent liquid is realized in this way:

In adjusting the collimation system 4, the moving mirror system 10, the beam splitting prism and its adjustment system 5, and the optical path compensator 11, in realizing the multi-band integrated multi-band Michelson interferometer of the present invention, the signal arm and the reference arm After the optical paths of the cuvettes are almost absolutely equal, the liquid to be tested is placed in the cuvette and its fixing system 9 . After being stabilized, the optical path scanning is realized by driving the moving mirror system 10 . After one scan, the signal processing unit 12 can obtain the white light interference spectrum of 8 bands.

Since light waves of different wavelength bands have different refractive indices in the same medium, in the embodiment shown in FIG. 7 , the geometric paths corresponding to the peaks in the white light interference spectrum of each band are different. In this way, the eight-band white light interference spectrum obtained in the embodiment shown in FIG. 7 will have peaks shifted from each other. By analyzing the displacement and the relationship between the refractive index and dispersion, the multi-band refraction and dispersion characteristics of the measured liquid can be obtained, so as to realize the multi-dimensional evaluation of the optical characteristics such as refraction and dispersion of the detected substance. This embodiment is suitable for the measurement and identification of transparent liquids, such as wines, sugar drinks, various edible vegetable oils, and various transparent medical injection liquids.

Claims (5)

1. a kind of integrated form multiband Michelson's interferometer, including photodetector, light source, collimator, Amici prism and its Adjustment system, stationary mirror, cuvette and its fixed system, mobile mirror system, optical path compensator and signal processing list Unit, is characterized in that：The photodetector is 8 wave band photodetectors, and described light source is wide spectrum light source, 8 band of light electrical resistivity surveys Survey device, wide spectrum light source, collimator, Amici prism and its adjustment system, stationary mirror, cuvette and its fixed system, movement Mirror system, optical path compensator and signal processing unit are integrated in composition 8 on same light base board and work in different ripples The Michelson's interferometer of section, the continuous light wave of wide spectrum light source output multiband, the light wave of each wave band is through Michelson Interferometer is respectively formed one group of white light interference pattern, by 8 each independent wave band photodetectors and signal processing unit simultaneously Realize each independent detection of 8 wave band white light interference signals.

2. integrated form multiband Michelson's interferometer according to claim 1, is characterized in that：The Amici prism and its Adjustment system is made up of Amici prism, Amici prism firm banking, firm banking angular adjustment frame, the firm banking angle The inside and outside contour line of adjustment frame is square, is provided with 4 in the vertical view face of firm banking angular adjustment frame and runs through Aperture, each aperture are centrally located at the symmetrical centre in each side face of adjustment frame, stand before and after firm banking angular adjustment frame 2 silk holes that runs through are had on face, and two on same facade silk hole is symmetrically distributed on the side face corresponding to the facade The both sides of opened aperture, the silk hole on former and later two facades are conllinear.

3. integrated form multiband Michelson's interferometer according to claim 2, is characterized in that：The Amici prism is fixed Base overlooks face for square, and the center for overlooking face is provided with a countersunk head through aperture；Amici prism is fixed with Amici prism Together, the downward projection face of prism is centrally located at the center that Amici prism firm banking overlooks face, and rib to floor installation The square four in the downward projection face of mirror is parallel when face square four is overlooked with firm banking.

4. integrated form multiband Michelson's interferometer according to claim 1 and 2, is characterized in that：Also include controlling into Enter the polarizer of the polarization state of each wave band light wave of Amici prism and its adjustment system, also include making 8 band of light electrical resistivity survey of entrance Survey the analyzer of the multiband light wave in identical polarization state of device.

5. integrated form multiband Michelson's interferometer according to claim 3, is characterized in that：Also include that control is entered to divide The polarizer of the polarization state of each wave band light wave of light prism and its adjustment system, also includes making 8 wave band photodetector of entrance Multiband light wave in identical polarization state analyzer.