WO2023029978A1

WO2023029978A1 - Wavefront-splitting one-way orthogonal optical path interferometer

Info

Publication number: WO2023029978A1
Application number: PCT/CN2022/112654
Authority: WO
Inventors: 董仕
Original assignee: 董仕
Priority date: 2021-09-01
Filing date: 2022-08-16
Publication date: 2023-03-09

Abstract

A wavefront splitting-based interferometer apparatus which is formed by means of an orthogonal beam combining manner, an optical transmission path of a reference beam and measurement beam of which is one-way, and which can be used for the precise measurement of physical parameters such as the anisotropic parameters, distance, speed, displacement, inclination angle, motion state, and flow velocity of a substance to be measured. An interference-based measurement means is a detection means in which by means of superposing two coherent optical signals that are spatially orthogonal, a two-signal phase difference is then derived by a superposed field intensity signal measured by a photoelectric sensor; and is a method that uses an observed phase difference when a spatial feature vector and effective beam of a target to be measured are perpendicular and parallel so as to inversely calculate the physical quantity of anisotropic features of the target. There are two basic types of design modes: one consists of a 2D plane structured optical path formed on the basis of a signal delayer and an optical path deflector (12), and the other consists of a 3D stereoscopic structured optical path formed on the basis of dual optical path deflectors (21, 22); and the two designs have the same function.

Description

Wavefront-splitting one-way orthogonal optical path interferometer

technical field

The invention belongs to the field of photoelectric detection and measuring equipment, and in particular relates to a wavefront division interferometer, a dual-frequency laser interferometer, a multi-frequency laser interferometer, a white light interferometer, and a white laser interferometer.

Background technique

Utilizing the interference principle of electromagnetic waves can produce very high-precision detection instruments. Various interferometers that have been commercialized now have a great impact on modern technology due to their excellent performance in laser gyroscopes, wavelength measurement, laser interferometric distance measurement, and refractive index measurement. Development plays a pivotal role. According to different design ideas, principles and uses, the existing interferometers mainly include Michelson interferometer, Mach-Zendr (MZ) interferometer, Segerac interferometer, thin-film interferometer, and Fresnel double-sided mirror interferometer. wait. However, with the development of science and technology, in some fields that require high-precision, optically anisotropic material (such as LiNbO₃, KDP, etc.) characteristic measurement, the aforementioned interferometer still cannot meet the measurement requirements. The main reason is that the aforementioned interferometers, except for a few interferometers such as Fresnel double-sided mirrors, all have a two-way round-trip or closed-path structure, and cannot perform high-precision measurements on these objects with optical anisotropy characteristic parameters, especially When it is necessary to dynamically monitor the input changes or output changes of different vectors, the use of existing related equipment for measurement will cause defects such as insufficient accuracy, real-time performance and reliability due to complicated operation and calculation steps; and Fresnel double-sided mirrors and the like The interferometer, because the traveling wave path does not adopt an orthogonal structure, leads to the disadvantages of complex system design, difficult mathematical modeling, and low comprehensive accuracy, which is not conducive to the precise measurement and analysis of the optical anisotropy parameters of the measurement object. Based on this, the inventor of this patent designed a wavefront segmentation interferometer with a one-way orthogonal structured optical path design, which can be used for the measurement of anisotropic characteristic parameters, and can also be used for applications such as motion state detection and flow velocity measurement. .

technical problem

The technical problem to be solved by the present invention is mainly aimed at the measurement of anisotropy parameters, providing a measurement method based on interference, which is based on the superposition of space orthogonal vector signals and deriving from the superposition field strength measured by the photoelectric sensor A detection method for the phase difference of two signals. When the spatial feature vector of the measured target is completely parallel and perpendicular to the direction of the effective measuring beam, the phase difference value proportional to the linear conversion of the measured feature quantity can be obtained.

technical solution

The present invention designs a one-way orthogonal optical path interferometer of the wave front split type, which is based on the wave front splitting of electromagnetic waves whose wave front is a plane, and at the same time designing the traveling wave path in the form of one-way propagation, and turning the traveling wave path They are all composed of an optical path structure that combines two beams of light in an orthogonal direction (when an array image sensor or image screen is used as an interference result detector, the image sensor can directly replace the original optical path combination In addition, the accuracy of the turning angle of the effective reference beam or the effective measuring beam does not need to be very high, but even so, its turning range generally does not exceed 90°±1 °). Specifically, the present invention provides three basic design frameworks, which will be introduced one by one next.

One is a wavefront-segmented one-way orthogonal optical path interferometer device based on a 2D structure design (see Figure 1), which is characterized in that parallel light whose wavefront is a plane wave is used as a light source (1), and by dividing the wavefront Enter the reference beam channel and the measurement beam channel respectively, the beam of the reference beam channel enters the effective reference beam working area after passing through an optical delay device (11), and the beam of the measuring beam channel enters after passing through a 90° optical path bender (12). Effectively measure the work area, by adjusting the position and attitude of the optical delay device (11) and the optical path bender (12), the axis lines (17, 18) of the two beams of light entering the effective area are orthogonal to the semi-transparent and semi-reflective The plane center of the reflective film layer of the mirror (13) combines beams, and the face angle (θ12, θ13) with the reflective film layer is the same as 45 ° (theta 12+ designed according to the optical characteristics of the existing half-transparent mirror) θ13=90° different-plane beam combination method), and at the same time, by adjusting the beam axis length Lr in the effective reference beam working area and the beam axis length Lm in the effective measurement working area are equal, by adjusting the optical delay device The amount of delay makes the time for the same wavefront emitted by the light source to reach the half-mirror at the same time in the initial state (it only needs to appear on the half-mirror at the same time, and the time phase is not required to be exactly the same, and the assembly error brings The phase offset can be calibrated during the initial test without strictly limiting the space-time position where the 0-order interference is located), and the combined interference beam is measured by an interference result detector (14) to obtain the reference beam and the measurement beam. Phase difference; in this scheme, if the space before and after the optical delay device has the same light propagation characteristics, there is no special constraint on the position of the optical delay device before and after the reference beam path. The attached drawings are only for the convenience of calculation and understanding and are not necessary Limiting conditions, but it must be satisfied that in the optically isotropic medium, and when the device and the medium are in a static state, the time increment of the beam passing through the delayer (relative to the optically isotropic medium) is equal to the length of the beam passing through Lm time consumed.

The other is a wavefront-segmented one-way orthogonal optical path interferometer device based on a 3D structure design (see Figures 2 to 4), which is characterized in that parallel light with a wavefront as a plane wave is used as a light source, and by dividing the wavefront The beams of the reference beam channel enter the effective reference beam working area after passing through a 90° optical path bender (21), and the beams of the measuring beam channel pass through a 90° optical path bender (22 ) into the effective measurement work area, the axis lines (27, 28) of these two beams of light entering the effective area are orthogonal to the half mirror (23 ) of the plane center of the reflective film layer is combined, and the angle (θ21, θ22) with the reflective film layer is 45° (theta21+θ22=90 designed according to the optical characteristics of the existing half-mirror) ° different-plane beam combination method), and at the same time, by adjusting the beam axis length L21 of the effective reference beam working area and the beam axis length L22 of the effective measurement work area to be equal, the interfering beam after beam combining passes through an interference result A detector (24) performs the measurement, obtaining the phase difference between the reference beam and the measurement beam.

The third type (see Fig. 5) is based on the aforementioned other implementation scheme, replacing the half mirror (23) with the front surface mirror (33), and moving a certain amount in the direction of the axis of the effective measuring beam. Distance and rotation at a certain angle, so that the effective reference beam and the effective measurement beam are directly combined and interfered on the interference result detector; the half mirror can also be replaced by two independent front surface mirrors, respectively for the effective The reference beam and the effective measurement beam are turned twice, and the turning vector should not have the traveling wave direction of the effective measurement beam, and the turning angle of the effective measurement beam needs to be 90° to simplify the difficulty of later data processing; On the basis of this implementation scheme, the half-mirror (23) is directly replaced by an array image sensor of nanoscale pixels to realize the detection of high-density interference fringes, and at the same time, the plane of the pixel and the half-mirror (23) are guaranteed The design plane should be consistent.

In the aforementioned three basic schemes, the interference result detector can be any device that can be used for interference result measurement such as an image screen, frosted glass, photodetector, image sensor; preferably, a photodetector or an array image sensor should be used , so that the superimposed field light intensity signal of the reference beam and the measurement beam is converted into an electrical signal, which is used to process and sample the signal through an existing traditional circuit and send it to an electronic computer for calculation and analysis. When the interference result detector is an array image sensor, it is necessary to adjust the light-receiving surface of the image sensor and the combined interference light wavefront to an attitude that is not strictly parallel, or adjust the wavefront of the effective reference beam to be in line with the effective measurement The not strictly vertical attitude of the beam wavefront enables it to obtain interference results above 0 order.

In the above three basic schemes, the spectral components of the parallel light source whose wavefront is a plane wave can be single-frequency laser, monochromatic light, white light, white laser, dual-frequency or multi-frequency laser, two-color or multi-color spontaneous emission light . For the stability and accuracy of the measurement results, polychromatic light is preferred as the light source, and the phase shift value of the combined frequency is solved by detecting the displacement of the 0-order interference on the interference result detector, or the fractional part of the phase shift of each frequency point simultaneously. Obtain more stable and accurate results and a larger range (see Tilford C R. Analytical procedure for determining lengths from frac2 national fringes[J]. Applied Optics, 1987 ,16(7)); when a polychromatic light source is used, the interference result detector can be equipped with a wave division multiplexer inside to avoid the problem of superimposed response when using photodetectors as the interference result detector; In addition to using the method of wavefront division to obtain coherent light, it is also possible to use two lasers with the same frequency or a stable frequency difference and a frequency difference not exceeding 100MHZ as the light source of the effective reference beam and the light source of the effective measurement beam, and The parallel light source, the optical delay device, and the optical path bender of the aforementioned scheme are replaced, and the direction and length of the effective reference beam and the effective measurement beam are respectively kept unchanged, so as to achieve the detection result of the same technical index.

In the aforementioned three basic schemes, the optical path deflector and the half-mirror can be installed on a motion mechanism that can move back and forth along the axis of the effective beam, and the whole set of devices can be installed on a two-dimensional turntable such as theodolite, The device has the functions of measuring spatial wavelength, exchanging reference/measurement channels, self-calibration, and self-calibration.

In the aforementioned schemes 1 and 2, a set of auxiliary detectors can be installed on the traveling wave optical path of the secondary beams after the coherent combination of half-mirrors to check the beam direction, beam quality, and wavefront distortion of the reference beam and the measuring beam. , and spectral components and other parameters are monitored as reference signals for automatic calibration, correcting assembly errors and parameter drift; through focusing imaging on the reference beam and the measuring beam, and using an area array image sensor, four-quadrant detector, etc. to measure the beam inclination angle The detection can be used for purposes such as self-calibration, sunlight or starlight tracking, and the parallel light source in the present invention can be replaced by sunlight or starlight to achieve higher-precision measurement (because the measurement accuracy is proportional to the length of the effective measurement beam, and the system integration It is difficult for a light source to achieve a large beam diameter while ensuring small wavefront distortion).

The typical use method of the wavefront split type one-way orthogonal optical path interferometer is to pre-adjust the device on the attitude that is irrelevant to the measurement, and read the initial phase difference of the device, and then fill or install the light anisotropic light to be measured The propagation medium is in the effective reference work area and the effective measurement work area, or the attitude of the device is adjusted so that the vector to be measured and the measurement beam/reference beam maintain a parallel/perpendicular relationship, so that the phase difference between the effective reference beam and the effective measurement beam is different from the initial state, through It is a method to obtain the anisotropy parameter of the measured object by capturing the variation of the phase difference. When used as motion and fluid detection, the attitude of the interferometer should be adjusted so that the effective measurement beam remains parallel to the motion/flow vector.

Definition of terms: In the present invention, the spatial area where the reference beam passes through the optical path bender or optical delay device and before the interference beam combination is called the effective reference beam working area, and this section of the beam is called the effective reference beam; The space area where the measuring beam passes through the optical path bender and before the interference beam combination is called the effective measuring beam working area, and this section of the beam is called the effective measuring beam; these two beam working areas are collectively called the effective working area , and these two beams are collectively called the effective beam. In addition, the terms of mathematics or geometric relations used in the present invention (such as plane wave, orthogonal, parallel, simultaneous, equal, etc.) are all measured by engineering practical standards, rather than ideal mathematics or geometry without any deviation. Generally speaking, it only needs to be more than twice the resolution of the relevant specific device or component. In the present invention, the initial state is not particularly limited, because different test objects require different initial states to obtain the most suitable results, but there are also some measurements that need to limit the initial state, such as motion and fluid measurement, The initial state should be static, or the initial state in which the plane formed by the effective light beam and the measured vector has an orthogonal relationship is the best initial state.

Beneficial effect

The invention is not only suitable for detecting optical crystal materials with optical anisotropy, but also can measure the anisotropy parameters of gaseous, plasma and field substances; it can be applied to motion state detection, flow velocity measurement, etc.; the present invention The unidirectional transmission structure of the optical path can avoid light pollution caused by light feedback while ensuring high working light efficiency; in addition, the present invention completely inherits the Michelson interferometer in terms of distance measurement, speed measurement, displacement measurement, and inclination measurement. , Mach-Zendr (MZ) interferometer and other traditional interferometers have the function.

Description of drawings

Fig. 1 is a front-view schematic diagram of an embodiment of a wavefront-segmented single-pass orthogonal optical path interferometer based on a 2D structure design.

Fig. 2 is a schematic top view of an embodiment of a wavefront-segmented one-way orthogonal optical path interferometer based on a 3D structure design.

Fig. 3 is a schematic oblique view of an embodiment of a wavefront-segmented one-way orthogonal optical path interferometer based on a 3D structure design.

Fig. 4 is a parameter annotation diagram of an embodiment of a wavefront split type one-way orthogonal optical path interferometer based on a 3D structure design.

Fig. 5 is a top view schematic diagram of an embodiment of a wavefront-segmented one-way orthogonal optical path interferometer based on a 3D structure design and using front surface mirrors for coherent beam combining.

In Fig. 1: 1) parallel light source; 11) optical delay device; 12) measuring beam front surface reflector; 13) semi-transparent semi-anticoherent beam combining mirror; 14) interference result detector; 15) auxiliary detector; 16) Reference wavefront position of parallel light; 16-1) Axis line of divided reference beam; 16-2) Axis line of divided measuring beam; 17) Axis line of effective reference beam; 18) Effective measurement Axis of beams; 19) Axis of primary beams after coherent combining; 10) Axis of secondary beams after coherent combining.

In Figures 2 to 4: 2) parallel light source; 21) reference beam front surface reflector; 22) measurement beam front surface reflector; 23) semi-transparent and semi-inverse coherent beam combiner; 24) interference result detector; 25) Auxiliary detector; 26) reference wavefront position of parallel light; 26-1) axis of divided reference parallel beam; 26-2) axis of divided measuring parallel beam; 27) axis of effective reference beam 28) The axis line of the effective measurement beam; 29) The axis line of the main beam after coherent beam combining; 20) The axis line of the secondary beam after coherent beam combining.

In Fig. 5: 2) parallel light source; 21) reference beam front surface mirror; 22) measurement beam front surface mirror; 33) front surface reflection beam combining mirror; 24) interference result detector; 26) reference beam for parallel light Wavefront position; 26-1) the axis of the divided reference parallel beam; 26-2) the axis of the divided measuring parallel beam; 27) the axis of the effective reference beam; 28) the axis of the effective measurement beam 29) axis of the effective reference beam in the interference zone.

BEST MODE FOR CARRYING OUT THE INVENTION

The implementation of the wavefront split type one-way orthogonal optical path interferometer based on the 3D structure design (see the schematic diagrams shown in Figures 2 to 4).

The parallel light source is selected as the disk laser and the multispectral laser generated after nonlinear frequency doubling is used as the light source; the silver-plated front surface reflector is selected as the optical path bender (21, 22), and a 45-degree inclined plane is selected for installation The optical adjustment frame of the semi-transparent and semi-reflective cube is selected as the coherent beam combiner (23), and the four transparent surfaces of the semi-transparent and semi-reflective cube are coated with anti-reflection coatings. The wave surface of the outgoing light is parallel, and the installation orientation of the light cube should make the reflected light vector the same as the outgoing light vector of another effective beam, and select an optical adjustment frame that does not block the four light-transmitting surfaces as the installation basis; Select a multi-channel photodetector with wave division multiplexing as the interference result detector (24); select an auxiliary detector (25) with an internal beam splitting device and an imaging lens for beam inclination measurement and spectrum measurement; in addition , a custom-made abutment conforming to the layout of the schematic diagram is also required as the basis for the installation of various components and components, and the installation parameters that need to be guaranteed are: the front surface of the optical path bender (21, 22) and the wave array emitted by the light source The surface is 45 degrees, and the axis lines of the two outgoing beams after passing through the optical path deflector are orthogonal [implicitly, satisfying the intersection line of the wavefront with the reflective surface when passing through the intersection of the axis lines of the incident-reflected beams, Be 90 degree orthogonal relations with the axis line of these two bundles of light, promptly θ27, θ28 are 90 degree among the accompanying drawing 4], the reflection film surface of coherent beam combining mirror (23) and the folder of effective reference beam axis line The angle θ21 and the angle θ22 between the axis of the effective measuring beam are both 45 degrees (theta12+θ13=90° different-plane beam combination method designed according to the optical characteristics of the existing half-mirror. This relationship also implies Note: the angles <θ23, θ24> between the intersection lines of the respective wavefronts and the reflective film surface relative to the respective axis lines are both 90 degrees, see the label in Figure 4), and the effective reference beam axis length L21 and the effective measurement The beam axis lengths L22 are equal, and in this embodiment, L21=L22=38.5mm.

Further, put the whole device into a darkroom or a light-proof cavity after all the aforementioned parts and components are installed in place; each output of the interference result detector (24) is connected to the multi-channel phase meter; the parallel light source is started, and the interference The effective beam plane of the result detector (24) is adjusted to a pose that has nothing to do with the measured vector. After the phase indications of the photodetectors of the interference result detector (24) are stabilized, record the phase initial value respectively, and set up in parallel. Solve for the phase value of the combined frequency. In this embodiment, if the light source needs to be replaced by a non-laser light source, it is also necessary to adjust the frame of the reflector so that the optical paths of the reference light and the measurement light are equal, that is, the phases of each photodetector are 0 at the same time (at this time the light In order to obtain the best signal-to-noise ratio of white light interference and a large range index, in addition to recording the displacement of the adjustment frame during the measurement , can also be used to assist in the realization of large-scale design.

Finally, load the sample in the effective working area, or adjust the attitude of the device so that the equal intensity surface of the measured field is parallel to the effective measurement beam wavefront, or the measured motion/flow vector is parallel to the effective measurement beam, and then record again For the phase value or frequency shift value of each photodetector, first solve the phase value of the combined frequency through the simultaneous equations, and then analyze the phase change or frequency change and the measured value according to the measured physical correlation mathematical formula. Measure the mapping relationship of physical quantities to achieve the purpose of measuring the anisotropic characteristic parameters of the target object. Preferably, these mathematical formulas related to physics should be compiled into application programs, so as to perform automatic calculations and output various related reports.

The above-mentioned specific embodiments are only used to understand the adjustment method, parameters and implementation steps of the best implementation mode, and are not intended to limit the implementation of the present invention. Those skilled in the art should be able to use known technologies and the realization methods and implementation methods recorded in the content of the present invention. Principles for flexible configuration and implementation.

Embodiments of the present invention

1. Implementation of a wavefront-segmented one-way orthogonal optical path interferometer based on 2D structure design (see the schematic diagram shown in Figure 1).

Select a parallel light source based on an argon ion multispectral laser and expand the parallel beam to a diameter of 100mm as a light source (1); select an ultra-low dispersion glass column with a refractive index of 1.43 and a length of 100mm as an optical delay device (11) , the two light-transmitting surfaces of the glass column are finely ground and polished, and then plated with an anti-reflection coating for visible light; the silver-plated front surface reflector is selected as the optical path bender (12), and an optical adjustment frame installed on a 45-degree inclined plane is selected for it as Installation basis; select the sandwich structure of glass-transflective film-glass as the semi-transparent and semi-reflective coherent beam combiner (13), wherein the thickness and material of the glass on both sides of the semi-transparent and semi-reflective film are the same, and the outer surface is coated with The best angle of incidence for the design of the transparent film and the half-mirror is 45 degrees, and an optical adjustment frame installed on a 45-degree inclined plane is selected as the installation basis; an area-array color industrial camera is selected as the interference result detector (14); in addition In addition, a high-dispersion rate rutile glass slide is prepared to adjust the dispersion generated by the optical delay device (11), and a custom-made abutment that conforms to the layout of the schematic diagram is used as the basis for the installation of various components and components, and the installation needs to be guaranteed The parameters are as follows: the two light-passing surfaces of the optical delay device (11) are parallel to the incident/exiting wavefront of the light source, and the front surface of the optical path deflector (12) is in a 45-degree relationship to the wavefront exiting the light source. [make the included angle θ 11 of the axis of the incident beam and the axis of the reflected beam in accompanying drawing 1 equal to 90°], the included angle of the reflective film surface of the semi-transparent and semi-inverted coherent beam combining mirror (13) and the axis of the reflected beam θ12 and the included angle θ13 of the central line of the outgoing light beam of the light delay device are all 45 degree relations, the center distance Lr from the light exit surface of the light delay device (11) to the half-mirror is about 43mm, and the optical path bender (12 ) is also about 43mm away from the center Lm of the half mirror.

Further, after installing all the above-mentioned components and components in place, put the whole device into a dark room or a light-proof cavity; connect the output video of the industrial camera to the computer, and start its video preview management software; start the parallel light source, and observe the computer screen. Whether the interference fringes are equal-thickness interference fringes, and the fringe spacing is suitable for identifying the distribution position of each chromatographic interference fringe, if it is not appropriate, adjust the optical Adjust the frame to meet the aforementioned conditions; find out whether the interference fringes have blue or green borders and bright and clear interference fringes, and gradually change the ratio of Lm to Lr by adjusting the mounting seat of the half-transparent mirror or the front surface reflector Search, if you still can't find it, you need to use the prepared rutile slide to compensate. The specific compensation method is to first make the wavefront parallel to the light-transmitting surface of the slide, and place the slide in the working area of the measuring beam close to the light source Then continue to search and search through the aforementioned method. When the interference fringe without fringe is still not found, slowly rotate the angle between the light-transmitting surface of the glass slide and the wavefront and repeat the aforementioned steps until the fringe appears to complete the initial adjustment. The purpose of finding the fringe-free interference fringes is to calibrate the measurement, that is, to determine the initial position of the 0-order interference. In addition, calling the 0-order interference fringes on the photosensitive surface of the camera is also to replace the laser source light with a non-laser light source. One of the efficient adjustment methods of the process.

Finally, through proper placement and fine-tuning of the interference device, in order to read the appropriate initial position of 0-order interference fringes, then load the sample in the effective working area, or adjust the posture of the device so that the iso-intensity surface of the measured field Parallel to the wavefront of the effective measurement beam, or the measured motion vector maintains a parallel relationship with the axis of the effective measurement beam, and then re-record the position changes of the interference fringes without fringe to calculate the displacement of the 0-order interference. The mathematical formula of the physical correlation between the measured physical quantity and the displacement, and the mapping relationship between the displacement and the measured physical quantity are analyzed to achieve the purpose of measurement. Preferably, these mathematical formulas related to physics should be compiled into application programs, so as to perform automatic calculations and output various related reports.

The above-mentioned specific embodiments are only used to understand the installation and adjustment method, parameters and implementation steps of the device 1 of the typical embodiment, and are not intended to limit the implementation of the present invention. Those skilled in the art should be able to use known technologies and the implementation methods and methods recorded in the content of the present invention. The principle of realization is flexible configuration and implementation.

2. An implementation of a wavefront-segmented one-way orthogonal optical path interferometer based on a 3D structure design and using front surface mirrors for coherent beam combining.

This embodiment is on the best implementation mode of the present invention, by replacing the half mirror with the front surface reflector (33), and moving a certain distance and rotating a certain angle in the direction of the axis of the effective measurement beam, so that The effective reference beam and the effective measuring beam are directly combined on the interference result detector (24) and interfered, and after redesigning the installation chassis, it can be realized by adopting the installation and adjustment method of the foregoing embodiment. It is also possible to replace the half-mirror with two independent front-surface reflectors to perform secondary turning on the effective reference beam and the effective measuring beam respectively. The turning vector should try to avoid the traveling wave direction vector of the effective measuring beam and effectively measure The turning angle of the beam is as close to 90° as possible to simplify the difficulty of data processing in the later stage, and the same purpose can be achieved. The advantage of using 2 turns is to avoid unequal dispersion, wavefront distortion, and additional harmful interference caused by half mirrors result. As a preference, the interference result detector (24) should adopt an array type color image sensor when using 2 turns.

For the specific implementation of the aforementioned three embodiments (including the best mode), devices of the same function and different types can be exchanged arbitrarily in different embodiments, and the materials and assembly methods not recorded in the specific implementation can also be The implementation is carried out according to the functions and known technologies of the corresponding devices, as well as the methods and materials described in the Summary of the Invention, and is not limited as the materials and implementation methods in implementation. For example, the optical path adjusted by the laser may be more suitable for high-reliability measurement occasions to use sunlight, starlight, and spontaneous radiation as light sources, which can avoid problems such as range out-of-bounds when using lasers; The minimalist system structure composed of lasers or frequency difference locked lasers can avoid negative results such as measurement errors caused by wavefront distortion and other effects. Therefore, as researchers in this industry, there is no need to follow the inventor's specific implementation method as the only way to realize the content of the present invention. Choose an appropriate method for research and implementation based on technical expertise and resource advantages.

Industrial Applicability

The industrial applicability of the present invention is mainly reflected in: the market demand is clear, with the development of industries such as optical functional materials, integrated optics, and high-precision measurement in recent years, there are a large number of technical indicators in subdivided fields that are difficult to complete with existing equipment. Especially the technical indicators that the user market attaches great importance to, such as single-time, directional, and dynamic monitoring.

Secondly, in terms of equipment construction raw materials and technical methods, all parts of the present invention have mature accessories on the market, and only need to design and manufacture some basic components to realize. In addition, all kinds of collected data in the present invention are realized by photoelectric sensors, which are convenient for connection with computer systems to complete various calculations and network processing in the later stage.

Finally, in terms of cost performance, because the present invention inherits and surpasses the existing related equipment in function, the main technical indicators can reach or even exceed the existing equipment, while the main components are the same parts of the existing equipment , in line with the trend of product survival and development, and can effectively promote the development of productivity.

Claims

A wavefront-segmented one-way orthogonal optical path interferometer device based on a 2D structure design, characterized in that parallel light with a wavefront as a plane wave is used as a light source, and the wavefront is divided into a reference beam channel and a measurement beam channel respectively , the beam of the reference beam channel enters the effective reference beam working area after passing through an optical delay device (11), and the beam of the measuring beam channel enters the effective measurement working area after passing through a 90° optical path bender (12). The position and attitude of the timer (11) and the light path reversing device (12) make the axes (17, 18) of these two beams of light entering the effective area orthogonal to the reflective film layer of the half-transparent mirror (13). Combine the beam, and the included angle (θ12, θ13) with the reflective film layer is the same as 45°, and at the same time, adjust the beam axis length Lr in the effective reference beam working area and the beam axis length in the effective measurement working area Lm is equal, by adjusting the delay amount of the optical delay device, the time for the same wavefront emitted by the light source to reach the half-mirror in the initial state is the same, and the combined interference beam passes through an interference result detector (14) A measurement is performed to obtain the phase difference between the reference beam and the measurement beam.
A wavefront-segmented one-way orthogonal optical path interferometer device based on a 3D structure design, characterized in that parallel light with a wavefront as a plane wave is used as a light source, and the wavefront is divided into a reference beam channel and a measurement beam channel respectively , the beam of the reference beam channel enters the effective reference beam work area after passing through a 90° optical path bender (21), and the beam of the measuring beam channel enters the effective measurement work area after passing through a 90° optical path bender (22), by adjusting The position and attitude of the light path reversing device (21, 22) make the axis lines (27, 28) of the two beams of light entering the effective area orthogonal to the reflective film layer of the half-transparent mirror (23) to combine the beams, and The included angles (θ21, θ22) with the reflective film layer are the same as 45°, and at the same time, the beam axis length L21 of the effective reference beam working area is equal to the beam axis length L22 of the effective measurement working area, and the combination The post-beam interference beam is measured by an interference result detector (24) to obtain the phase difference between the reference beam and the measurement beam.
Based on claim 1 or claim 2, the device is pre-adjusted at a posture that has nothing to do with the measured object, and the initial phase difference of the device is read, and then the effective reference work area is filled or installed with an anisotropic optical propagation medium to be measured and the effective measurement work area, or adjust the attitude of the device to keep the vector to be measured in a parallel/perpendicular relationship with the measurement beam/reference beam, so that the phase difference between the effective reference beam and the effective measurement beam is different from the initial state, by capturing the variation of the phase difference To find the method of anisotropy parameter.
Based on claim 1 or claim 2, the spectral components of the parallel light source whose wavefront is a plane wave are white light, white laser, dual-frequency or multi-frequency laser, dual-color or multi-color spontaneous emission light, by detecting 0-order interference in the interference As a result, the displacement on the detector, or the fractional part of the phase shift of each frequency point is simultaneously solved for the phase shift value of the combined frequency to achieve a larger measurement range.
Based on claim 1 or claim 2, the interference result detector is a photodetector, which converts the superimposed field light intensity signal of the reference beam and the measurement beam into an electrical signal, which is used to process the signal through an existing traditional circuit after sampling Send it to a computer for calculation and analysis.
Based on claim 1 or claim 2, the interference result detector is an array image sensor, and the light-receiving surface of the image sensor and the combined interference light wavefront are adjusted to a non-strictly parallel attitude, or the effective reference beam The wavefront of the wavefront is adjusted to an attitude that is not strictly perpendicular to the wavefront of the effective measurement beam, so that it can obtain interference results above 0 order.
Based on claim 1 or claim 2, a set of auxiliary detectors is installed on the traveling wave optical path of the secondary beams coherently combined by half-mirrors to check the beam direction, beam quality, wavefront distortion, and spectral components, etc. The parameters are monitored and used as reference signals for automatic calibration, correction of assembly errors and parameter drift.
Based on claim 2, the half mirror is replaced by a front surface reflector (33), and a certain distance is moved and a certain angle is rotated in the direction of the axis of the effective measurement beam, so that the effective reference beam and the effective measurement beam directly interfere As a result the beams combine on the detector and interfere.
Based on claim 1 or claim 2, the optical path deflector and the half-mirror are mounted on a motion mechanism that can move back and forth along the axis of the effective beam, so that the device has the ability to measure the spatial wavelength.
Based on claim 9, the entire device is installed on a two-dimensional turntable such as a theodolite, so that the device has functions such as automatic measurement, exchange of reference/measurement channels, self-calibration, and self-correction.