Dynamic interferometer based on AWG high-precision measurement

Abstract

The invention relates to a dynamic interferometer based on AWG high-precision measurement, and an array waveguide grating is used for splitting light beams entering an input port, so that the light beams with different wavelengths are respectively output from different output ports of the array waveguide grating. The light source, the first space lens group and the array waveguide grating are arranged on the displacement mechanism, and the displacement mechanism enables different output ports of the array waveguide grating to be aligned with the second space lens group. A half-wave plate of the interference assembly is located between a second space mirror set and a polarization beam splitter, the polarization beam splitter is used for dividing a light beam passing through the half-wave plate into reference light transmitted along a reference light path and measurement light transmitted along a measurement light path, and the reference light is reflected back to the polarization beam splitter through a reflection mirror surface. The measuring light is reflected back to the polarization beam splitter through the surface to be measured, the reference light and the measuring light which are reflected back to the polarization beam splitter interfere with each other, and an interference image is recorded in the detector, so that the accuracy of obtaining the wavefront image of the surface to be measured is higher.

Description

Technical Field

[0001] The invention belongs to the technical field of optical measurement, and in particular relates to a dynamic interferometer based on AWG high-precision measurement. Background Art

[0002] With the development of high technology, the requirements for the quality of optical systems in the fields of national economy, scientific research and national defense are getting higher and higher. Among them, the surface processing and detection of optical components are important links to ensure the quality of high-precision and high-quality optical systems. The wavefront shape detection of the plane, spherical and aspherical surfaces of optical components is generally completed using interferometers. Due to the advantages of high precision, high sensitivity and non-destructive testing, interferometers are widely used in various related detection fields. The existing interferometer measurement process is greatly affected by the wavelength jitter of the light source and environmental factors, and it is difficult to guarantee the measurement accuracy of each measurement. Summary of the invention

[0003] In view of this, the present invention aims to provide a dynamic interferometer based on AWG (Arrayed Waveguide Grating) high-precision measurement to obtain a wavefront image of the surface to be measured with higher accuracy.

[0004] To achieve the above object, the technical solution created by the present invention is implemented as follows: A dynamic interferometer based on AWG high-precision measurement, comprising a light source, a first space mirror group, an arrayed waveguide grating, a second space mirror group, a displacement mechanism, an interference component and a detector; The light source is used to emit a light beam; The first spatial mirror group is arranged on the optical path from the light source to the input port of the arrayed waveguide grating, and is used to transmit the light beam emitted by the light source to the input port of the arrayed waveguide grating; the second spatial mirror group is arranged on the optical path from the output port of the arrayed waveguide grating to the interference component, and is used to transmit the light beam output from the output port of the arrayed waveguide grating to the interference component; The arrayed waveguide grating is used to split the light beam entering the input port so that light beams of different wavelengths are output from different output ports of the arrayed waveguide grating respectively; the light source, the first space mirror group and the arrayed waveguide grating are arranged on a displacement mechanism, and the displacement mechanism moves the light source, the first space mirror group and the arrayed waveguide grating so that different output ports of the arrayed waveguide grating are aligned with the second space mirror group; The interference component includes a half wave plate, a polarization beam splitter and a reflecting mirror; the half wave plate is located between the second space mirror group and the polarization beam splitter, the polarization beam splitter is used to split the light beam passing through the half wave plate into a reference light transmitted along a reference light path and a measurement light transmitted along a measurement light path, the reference light is reflected back to the polarization beam splitter through the reflecting mirror, the measurement light is reflected back to the polarization beam splitter through the surface to be measured, the reference light and the measurement light reflected back to the polarization beam splitter interfere with each other, and the interference image is recorded on the detector.

[0005] Furthermore, the first spatial mirror group includes a first collimating lens and a focusing lens, the focus of the first collimating lens is aligned with the input port of the arrayed waveguide grating, and the focusing lens is located on the optical path from the first collimating lens to the input port of the arrayed waveguide grating.

[0006] Furthermore, the second spatial mirror group includes a beam expander and a second collimating lens, the focus of the beam expander is aligned with any output port of the arrayed waveguide grating, and the second collimating lens is located on the optical path from the beam expander to the interference component.

[0007] Furthermore, the channel wavelength interval of the arrayed waveguide grating ranges from 0.01 nm to 0.1 nm.

[0008] Further, the interference assembly also includes a first quarter wave plate arranged in the reference optical path, and the first quarter wave plate is located between the polarization beam splitter and the reflective mirror surface; The reference light passes through the first quarter wave plate and is incident on the surface of the reflective mirror. After being reflected from the reflective mirror, the reference light passes through the first quarter wave plate again and is reflected back to the polarization beam splitter.

[0009] Furthermore, the interference assembly further includes a second quarter wave plate and a focusing lens arranged in the measuring light path, the surface to be measured is arranged in the measuring light path, and the focusing lens is located between the second quarter wave plate and the surface to be measured; The measuring light passes through the second quarter wave plate and the focusing lens, is incident on the surface of the surface to be measured, is reflected from the surface of the surface to be measured, passes through the focusing lens and the second quarter wave plate again, and is reflected back to the polarization beam splitter.

[0010] Further, the interference assembly also includes a third quarter wave plate, and the third quarter wave plate is located between the polarization beam splitter and the detector; The reference light and the measurement light reflected back to the polarization beam splitter interfere with each other after passing through the third quarter-wave plate, and the interference image is recorded on the detector.

[0011] Furthermore, the detector is a polarization camera.

[0012] Compared with the prior art, the invention can achieve the following beneficial effects: The dynamic interferometer based on AWG high-precision measurement created by the present invention can realize the frequency stabilization and screening of the wavelength of the light beam emitted by the light source through the array waveguide grating, so as to realize the accurate measurement of the wavefront image of the surface to be measured. The array waveguide grating is used as a spectroscopic element, and the wavelength of the light beam emitted by the light source can be accurately controlled, which provides a basis for the surface shape detection of the surface to be measured of the optical element. Among them, the light beam emitted by the light source is diffracted and split by the array waveguide grating, so that light beams of different wavelengths are output through different output channels of the array waveguide grating, so that each output port of the array waveguide grating can output a light beam with a narrow line width and stable wavelength. And the light source, the first space mirror group and the array waveguide grating are arranged in a displacement mechanism, and the light source, the first space mirror group and the array waveguide grating can be driven to move through the displacement mechanism, so that different output ports of the array waveguide grating are aligned with the second space mirror group. Different output ports of the array waveguide grating can output light beams of different wavelengths, so that the displacement mechanism can be used to realize multi-wavelength rapid measurement, so that the accuracy of the wavefront image of the surface to be measured is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 It is an optical structure diagram of a dynamic interferometer based on AWG high-precision measurement according to an embodiment of the present invention; Figure 2 This is a diagram of the spectroscopic effect of the arrayed waveguide grating of the dynamic interferometer based on AWG high-precision measurement described in the embodiment of the present invention.

[0014] Description of reference numerals: A dynamic interferometer 10 based on AWG high-precision measurement; a light source 11; a first space mirror group 12; an arrayed waveguide grating 13; a second space mirror group 14; an interference component 15; a detector 16; a half wave plate 17; a beam splitter 18; a reflecting mirror 19; a surface to be measured 20; a first collimating lens 21; a focusing objective lens 22; a beam expander 23; a second collimating lens 24; a first quarter wave plate 25; a second quarter wave plate 26; a focusing lens 27; and a third quarter wave plate 28. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantages of the invention clearer, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the invention and do not constitute a limitation to the invention. Similar components in different embodiments use associated similar component numbers. In the following embodiments, many detailed descriptions are to enable the invention to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other components, materials, and methods. In some cases, some operations related to the invention are not shown or described in the specification, in order to avoid the core part of the invention being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0016] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to form various implementation methods. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a necessary sequence, unless otherwise specified that a certain sequence must be followed.

[0017] In the description of the invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, the meaning of "multiple" is two or more.

[0018] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0019] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0020] See also Figure 1 As shown, the present invention provides a dynamic interferometer 10 based on AWG high-precision measurement, which can be used for wavefront shape detection of optical elements. The dynamic interferometer 10 based on AWG high-precision measurement includes a light source 11, a first space mirror group 12, an arrayed waveguide grating 13, a second space mirror group 14, a displacement mechanism (not shown in the figure), an interference component 15 and a detector 16.

[0021] The light source 11 is used to emit a light beam. The light source 11 may be a broad-spectrum light source, or may be a laser emitter for emitting a laser beam.

[0022] The first space mirror group 12 is arranged on the optical path from the light source 11 to the input port of the arrayed waveguide grating 13, and is used to transmit the light beam emitted by the light source 11 to the input port of the arrayed waveguide grating 13. In one embodiment, the first space mirror group 12 includes a first collimating lens 21 and a focusing lens 22, the focus of the first collimating lens 21 is aligned with the input port of the arrayed waveguide grating 13, and the first collimating lens 21 is used to collimate the light beam emitted by the light source 11. The focusing lens 22 is located on the optical path from the first collimating lens 21 to the input port of the arrayed waveguide grating 13, and the focusing lens is used to focus the light beam collimated by the first collimating lens 21 to the input port of the arrayed waveguide grating 13. Thereby, the light beam emitted by the light source 11 can be transmitted to the input port of the arrayed waveguide grating 13 through the first space mirror group 12.

[0023] The second space mirror group 14 is arranged on the optical path from the output port of the arrayed waveguide grating 13 to the interference component 15, and is used to transmit the light beam output from the output port of the arrayed waveguide grating 13 to the interference component 15. In one embodiment, the second space mirror group 14 includes a beam expander 23 and a second collimator lens 24. The focus of the beam expander 23 is aligned with any output port of the arrayed waveguide grating 13. The focus of the beam expander 23 can be aligned with one of the multiple output ports of the arrayed waveguide grating 13. The beam expander 23 can adjust the size and divergence angle of the light beam output from the output port of the arrayed waveguide grating 13, so as to facilitate coupling with the second collimator lens 24. The second collimator lens 24 is located on the optical path from the beam expander 23 to the interference component 15. The second collimator lens 24 is used to collimate the light beam output from the beam expander 23 and transmit it to the interference component 15. Thereby, the light beam output from the output port of the arrayed waveguide grating 13 can be transmitted to the interference component 15 through the second space mirror group 14.

[0024] The arrayed waveguide grating 13 (AWG) is used to split the light beam entering the input port so that light beams of different wavelengths are output from different output ports of the arrayed waveguide grating 13 respectively, which can achieve high-precision splitting of the spectrum, so that light beams of different wavelengths pass through different output channels of the arrayed waveguide grating 13 respectively and are output from different output ports. In one embodiment, the channel wavelength interval of the arrayed waveguide grating 13 ranges from 0.01nm to 0.1nm. In this embodiment, the channel wavelength interval of the arrayed waveguide grating 13 is 0.01nm, and the wavelength resolution is high, so that the measurement accuracy of the wavefront shape detection of the optical element is higher. See Figure 2 As shown, Figure 2 The horizontal axis shown in is the wavelength, and the vertical axis is the transmission loss of the light beam. Figure 2The lines of different colors shown in the figure represent different output channels, the dark blue line represents channel 1, the green line represents channel 2, the red line represents channel 3, and the light blue line represents channel 4. Taking channel 1 as an example, at the half-wave peak position, that is, when the transmission loss of the light beam is -20dB, the corresponding wavelengths of the horizontal axis are 700.01nm and 700.02nm, and the difference between the two is 0.01nm, which shows that the wavelength resolution of the arrayed waveguide grating 13 is 0.01nm. The light source 11, the first space mirror group 12 and the arrayed waveguide grating 13 are all arranged in a displacement mechanism, and the displacement mechanism moves the light source 11, the first space mirror group 12 and the arrayed waveguide grating 13 so that different output ports of the arrayed waveguide grating 13 are aligned with the second space mirror group 14. The displacement mechanism moves the light source 11, the first space mirror group 12 and the arrayed waveguide grating 13, and can realize the movement of the light source 11, the first space mirror group 12 and the arrayed waveguide grating 13 along the arrangement direction of the multiple output ports of the arrayed waveguide grating 13, so as to switch the different output channels of the arrayed waveguide grating 13, so that the different output ports are aligned with the focus of the beam expander 23 of the second space mirror group 14. The light beam output from the output port of the arrayed waveguide grating 13 can enter the second space mirror group 14, and be transmitted to the interference component 15 through the second space mirror group 14. In one embodiment, the displacement mechanism includes a driving structure and a transmission component, and the driving structure can be a structure such as a motor. The transmission component adopts any of the following components: a chain transmission component, a gear rack component, a lead screw nut component, etc. The output end of the driving structure is connected to the transmission component to realize the action of the transmission component, thereby moving the light source 11, the first space mirror group 12 and the arrayed waveguide grating 13.

[0025] The interference assembly 15 includes a half wave plate 17, a polarization beam splitter 18 and a reflective mirror 19. The half wave plate 17 is located between the second space mirror group 14 and the polarization beam splitter 18, and the polarization beam splitter 18 is used to split the light beam passing through the half wave plate 17 into a reference light transmitted along the reference light path and a measurement light transmitted along the measurement light path. In this embodiment, the light beam output from the output port of the array waveguide grating 13 is transmitted to the half wave plate 17 through the second space mirror group 14, and is incident on the polarization beam splitter 18 through the half wave plate 17, and is divided into P polarized light as a reference light and S polarized light as a measurement light with polarization directions perpendicular to each other through the polarization beam splitter 18. The reflective mirror 19 is arranged in the reference light path, and the reference light is reflected back to the polarization beam splitter 18 through the reflective mirror 19. The surface to be measured 20 is arranged in the measurement light path, and the measurement light is reflected back to the polarization beam splitter 18 through the surface to be measured 20. The reference light and the measuring light reflected back to the polarization beam splitter 18 interfere with each other, and an interference image is recorded on the detector 16 .

[0026] The dynamic interferometer 10 based on AWG high-precision measurement created by the present invention can achieve frequency stabilization and screening of the wavelength of the light beam emitted by the light source 11 through the arrayed waveguide grating 13, so that the wavefront image of the surface to be measured 20 can be measured more efficiently and accurately. The arrayed waveguide grating 13 is used as a spectroscopic element, and the wavelength of the light beam emitted by the light source 11 can be accurately controlled, which provides a basis for the surface shape detection of the surface to be measured 20 of the optical element. Among them, the light beam emitted by the light source 11 is diffracted and split by the arrayed waveguide grating 13, so that light beams of different wavelengths are output through different output channels of the arrayed waveguide grating 13, so that each output port of the arrayed waveguide grating 13 can output a light beam with a narrow line width and stable wavelength. And the light source 11, the first space mirror group 12 and the arrayed waveguide grating 13 are all arranged in a displacement mechanism, and the displacement mechanism can drive the light source 11, the first space mirror group 12 and the arrayed waveguide grating 13 to move, so that different output ports of the arrayed waveguide grating 13 are aligned with the second space mirror group 14. Different output ports of the arrayed waveguide grating 13 can output light beams of different wavelengths, so that a displacement mechanism can be used to achieve multi-wavelength rapid measurement, thereby obtaining a wavefront image of the measured surface 20 with higher accuracy. At the same time, compared with the traditional dynamic interferometer, the dynamic interferometer 10 based on AWG high-precision measurement created by the present invention has a simpler optical structure, and the light source 11 can be a wide-spectrum light source, which reduces the cost.

[0027] In this embodiment, the first collimating lens 21, the focusing lens 22, the arrayed waveguide grating 13, the beam expander 23, the second collimating lens 24, the half wave plate 17, the polarization beam splitter 18 and the surface to be measured 20 are arranged in sequence along the first straight line direction. The reflecting mirror 19, the polarization beam splitter 18 and the detector 16 are arranged in sequence along the second straight line direction. The first straight line direction is perpendicular to the second straight line direction.

[0028] In one embodiment, the interference assembly 15 further includes a first quarter wave plate 25 arranged in the reference light path, and the first quarter wave plate 25 is located between the polarization beam splitter 18 and the reflection mirror 19. The reference light passes through the first quarter wave plate 25 and is incident on the surface of the reflection mirror 19. After being reflected from the reflection mirror 19, it passes through the first quarter wave plate 25 again and returns to the polarization beam splitter 18. In this embodiment, the P-polarized light serving as the reference light is transmitted through the first quarter wave plate 25 and converted into right-handed polarized light, which is incident on the reflection mirror 19. After being reflected from the reflection mirror 19, it passes through the first quarter wave plate 25 again and is modulated into S-polarized light, which is then reflected back to the polarization beam splitter 18.

[0029] In one embodiment, the interference assembly 15 further includes a second quarter wave plate 26 and a focusing lens 27 arranged in the measuring light path, the surface to be measured 20 is arranged in the measuring light path, and the focusing lens 27 is located between the second quarter wave plate 26 and the surface to be measured 20. The measuring light passes through the second quarter wave plate 26 and the focusing lens 27, is incident on the surface of the surface to be measured 20, is reflected from the surface of the surface to be measured 20, passes through the focusing lens 27 and the second quarter wave plate 26 again, and is reflected back to the polarization beam splitter 18. In this embodiment, the S polarized light as the measuring light is transmitted through the second quarter wave plate 26, is converted into left-handed polarized light, passes through the focusing lens 27 again, is incident on the surface of the surface to be measured 20, is reflected from the surface of the surface to be measured 20, passes through the focusing lens 27 and the second quarter wave plate 26 again, is modulated into P polarized light, and is reflected back to the polarization beam splitter 18.

[0030] In one embodiment, the interference assembly 15 further includes a third quarter wave plate 28, and the third quarter wave plate 28 is located between the polarization beam splitter 18 and the detector 16. The reference light and the measurement light reflected back to the polarization beam splitter 18 interfere with each other after passing through the third quarter wave plate 28, and the interference image is recorded on the detector 16. The reference light and the measurement light reflected back to the polarization beam splitter 18 are combined by the polarization beam splitter 18, and then pass through the third quarter wave plate 28, so that the reference light and the measurement light interfere with each other, and the interference image is recorded on the detector 16. In this embodiment, the modulated S polarized light as the reference light and the P polarized light as the measurement light are reflected back to the polarization beam splitter 18 for combination, and pass through the third quarter wave plate 28, so that the S polarized light as the reference light is converted into right-handed polarized light, and the P polarized light as the measurement light is converted into left-handed polarized light, so that the reference light and the measurement light interfere with each other, and the interference image is recorded on the detector 16.

[0031] In one embodiment, the detector 16 is a polarization camera. The detector 16 can use a high-resolution polarization camera. The polarization camera can be used to obtain four interference images with different phases in real time, and the interference images are sent to a computer for processing. The computer can obtain the wavefront image of the surface to be measured 20 at the current wavelength through a four-step phase shift solution. By using a displacement mechanism, different output ports of the arrayed waveguide grating 13 are aligned with the second spatial mirror group 14, and the wavefront images of the surface to be measured 20 at multiple different wavelengths can be obtained. The computer can obtain the wavefront image of the surface to be measured 20 by processing the wavefront images of the surface to be measured 20 at multiple different wavelengths, thereby realizing accurate measurement of the wavefront image of the surface to be measured 20. The detector 16 uses a polarization camera, and obtains all phase images required for computer calculation through a single exposure of the CCD sensor. Compared with the traditional dynamic interferometer, which needs to calculate each light intensity image separately, the error is smaller.

[0032] Compared with the traditional dynamic interferometer, it is necessary to adjust the angle of the reflective mirror several times to obtain the interference image. The dynamic interferometer 10 based on AWG high-precision measurement created by the present invention adopts the principle of polarization interference, and does not need to set the phase shift mechanism used by the traditional dynamic interferometer to adjust the angle of the reflective mirror. The time domain phase shift of the traditional phase shift interferometer is converted into a space domain phase shift, which effectively overcomes external interference and avoids the influence of adverse factors such as environmental vibration and airflow disturbance on the dynamic interferometer. Full-resolution measurement can be achieved within one CCD frame rate of the detector 16, realizing rapid measurement.

[0033] The dynamic interferometer 10 based on AWG high-precision measurement created by the present invention has the characteristics of fast measurement, high precision, high accuracy detection, and insensitivity to vibration, and can be adapted to measurements in harsh environments. It can also be adapted to scenarios such as large-sized optical elements or optical systems, long optical path measurements, and difficult tests, such as motion and resonance detection, and ultrafast process detection.

[0034] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0035] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A dynamic interferometer based on AWG high-precision measurement, characterized in that: It includes a light source, a first space mirror group, an arrayed waveguide grating, a second space mirror group, a displacement mechanism, an interference component and a detector; The light source is used to emit a light beam; The first spatial mirror group is arranged on the optical path from the light source to the input port of the arrayed waveguide grating, and is used to transmit the light beam emitted by the light source to the input port of the arrayed waveguide grating; the second spatial mirror group is arranged on the optical path from the output port of the arrayed waveguide grating to the interference component, and is used to transmit the light beam output from the output port of the arrayed waveguide grating to the interference component; The arrayed waveguide grating is used to split the light beam entering the input port so that light beams of different wavelengths are respectively output from different output ports of the arrayed waveguide grating; the light source, the first space mirror group and the arrayed waveguide grating are arranged on the displacement mechanism, and the displacement mechanism moves the light source, the first space mirror group and the arrayed waveguide grating so that different output ports of the arrayed waveguide grating are aligned with the second space mirror group; The interference component includes a half wave plate, a polarization beam splitter and a reflective mirror; the half wave plate is located between the second space mirror group and the polarization beam splitter, the polarization beam splitter is used to split the light beam passing through the half wave plate into a reference light transmitted along a reference light path and a measurement light transmitted along a measurement light path, the reference light is reflected back to the polarization beam splitter through the reflective mirror, the measurement light is reflected back to the polarization beam splitter through the surface to be measured, the reference light and the measurement light reflected back to the polarization beam splitter interfere with each other, and the interference image is recorded on the detector.

2. The dynamic interferometer based on AWG high-precision measurement according to claim 1, characterized in that: The first spatial mirror group includes a first collimating lens and a focusing lens. The focus of the first collimating lens is aligned with the input port of the arrayed waveguide grating. The focusing lens is located on the optical path from the first collimating lens to the input port of the arrayed waveguide grating.

3. The dynamic interferometer based on AWG high-precision measurement according to claim 1, characterized in that: The second spatial mirror group includes a beam expander and a second collimating lens. The focus of the beam expander is aligned with any of the output ports of the arrayed waveguide grating. The second collimating lens is located on the optical path from the beam expander to the interference component.

4. The dynamic interferometer based on AWG high-precision measurement according to claim 1, characterized in that: The channel wavelength interval of the arrayed waveguide grating ranges from 0.01 nm to 0.1 nm.

5. The dynamic interferometer based on AWG high-precision measurement according to claim 1, characterized in that: The interference assembly further comprises a first quarter wave plate arranged in the reference optical path, wherein the first quarter wave plate is located between the polarization beam splitter and the reflective mirror surface; The reference light passes through the first quarter wave plate and is incident on the surface of the reflective mirror. After being reflected from the reflective mirror, the reference light passes through the first quarter wave plate again and is reflected back to the polarization beam splitter.

6. The dynamic interferometer based on AWG high-precision measurement according to claim 1, characterized in that: The interference assembly further includes a second quarter wave plate and a focusing lens arranged in the measuring light path, the surface to be measured is arranged in the measuring light path, and the focusing lens is located between the second quarter wave plate and the surface to be measured; The measuring light passes through the second quarter wave plate and the focusing lens, is incident on the surface of the surface to be measured, is reflected from the surface of the surface to be measured, passes through the focusing lens and the second quarter wave plate again, and is reflected back to the polarization beam splitter.

7. The dynamic interferometer based on AWG high-precision measurement according to claim 1, characterized in that: The interference assembly further includes a third quarter wave plate, wherein the third quarter wave plate is located between the polarization beam splitter and the detector; The reference light and the measuring light reflected back to the polarization beam splitter interfere with each other after passing through the third quarter-wave plate, and an interference image is recorded on the detector.

8. The dynamic interferometer based on AWG high-precision measurement according to claim 1, characterized in that: The detector is a polarization camera.

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