Dynamic interferometer based on AWG high-precision stable amplitude measurement

Abstract

The invention relates to a dynamic interferometer based on AWG high-precision stable amplitude measurement. A light source is used for emitting light beams. The beam splitter is used for splitting an incident light beam into a first light beam and a second light beam according to the distribution proportion. The first light beam passes through the first focusing lens and is focused on the receiving surface of the light intensity sensor. The controller is used for adjusting the light intensity of the light beam emitted by the light source according to the difference value between the first light intensity detected by the light intensity sensor and the set light intensity. The second light beam enters the polarization beam splitter through the half-wave plate and is divided into reference light transmitted along the reference light path and measuring light transmitted along the measuring light path by the polarization beam splitter. And the reflecting mirror surface is used for reflecting the reference light back to the polarization beam splitter. The surface to be measured is used for reflecting the measuring light back to the polarization beam splitter. The reference light and the measuring light reflected back to the polarization beam splitter interfere with each other so as to be imaged on the target surface of the detector. Accurate measurement of the wavefront image of the surface to be measured can be realized.

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 stable amplitude 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 interferometers have poor measurement accuracy. Summary of the invention

[0003] In view of this, the present invention aims to provide a dynamic interferometer based on AWG (Arrayed Waveguide Grating) with high-precision stable amplitude measurement, which achieves the stabilization of the amplitude of the light beam emitted by the light source and can realize the accurate measurement of the wavefront image of the surface to be measured.

[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 stable amplitude measurement, comprising a light source, a beam splitter, a first focusing lens, a light intensity sensor, an interference component, a detector and a controller; The light source is used to emit a light beam; the beam splitter and the interference component are located on the optical path of the outgoing light beam of the light source, and the beam splitter is located between the light source and the interference component; the beam splitter is used to split the incident light beam into a first light beam and a second light beam according to a distribution ratio; The first light beam passes through the first focusing lens and is focused on the receiving surface of the light intensity sensor, and the light intensity sensor is used to detect the light intensity of the first light beam; the controller is used to adjust the light intensity of the light beam emitted by the light source according to the difference between the light intensity of the first light beam detected by the light intensity sensor and the set light intensity; The interference component comprises a half wave plate, a polarization beam splitter and a reflection mirror, wherein the half wave plate is arranged on the optical path from the beam splitter to the polarization beam splitter; the second light beam is incident on the polarization beam splitter through the half wave plate, and is split by the polarization beam splitter into a reference light transmitted along the reference light path and a measurement light transmitted along the measurement light path; the reflection mirror is arranged on the reference light path, and is used to reflect the reference light back to the polarization beam splitter; the surface to be measured is arranged on the measurement light path, and is used to reflect the measurement light back to the polarization beam splitter; the reference light and the measurement light reflected back to the polarization beam splitter interfere with each other, so as to form an image on the target surface of the detector.

[0005] Furthermore, it also includes a first space mirror group, an arrayed waveguide grating, a second space mirror group and a displacement mechanism, 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 space mirror group is arranged on the optical path from the output port of the arrayed waveguide grating to the beam splitter, and is used to transmit the light beam output from the output port of the arrayed waveguide grating to the beam splitter; 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.

[0006] Furthermore, the channel wavelength interval of the arrayed waveguide grating ranges from 0.01 nm to 0.1 nm.

[0007] Furthermore, the displacement mechanism includes a driving component and a linkage component, wherein the driving component is connected to the linkage component and is used to drive the linkage component to work so as to move the light source, the first spatial mirror group and the arrayed waveguide grating.

[0008] 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.

[0009] 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 beam splitter.

[0010] 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.

[0011] Furthermore, the interference assembly further includes a second quarter wave plate and a second focusing lens arranged in the measuring light path, the surface to be measured is arranged in the measuring light path, and the second 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 second focusing lens, is incident on the surface to be measured, is reflected from the surface to be measured, passes through the second focusing lens and the second quarter wave plate again, and is reflected back to the polarization beam splitter.

[0012] 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 are reflected back to the polarization beam splitter and form interference after passing through the third quarter-wave plate to form an image on the target surface of the detector.

[0013] Compared with the prior art, the invention can achieve the following beneficial effects: The dynamic interferometer based on AWG high-precision stable amplitude measurement created by the present invention has the function of dynamically monitoring the amplitude of the light beam emitted by the light source. The controller can adjust the intensity of the light beam emitted by the light source according to the difference between the intensity of the first light beam detected by the light intensity sensor and the set intensity, thereby achieving the stabilization of the amplitude of the light beam emitted by the light source and avoiding errors in the dynamic interferometer during the detection process, thereby obtaining more accurate measurement results and realizing accurate measurement of the wavefront image of the surface to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] 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 stable amplitude 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 stable amplitude measurement described in the embodiment of the present invention.

[0015] Description of reference numerals: Dynamic interferometer 10; light source 11; beam splitter 12; first focusing lens 13; light intensity sensor 14; interference assembly 15; detector 16; half wave plate 17; polarization beam splitter 18; reflecting mirror 19; surface to be measured 20; first space mirror group 21; array waveguide grating 22; second space mirror group 23; first collimating lens 24; focusing objective lens 25; beam expander 26; second collimating lens 27; first quarter wave plate 28; second quarter wave plate 29; second focusing lens 30; third quarter wave plate 31. DETAILED DESCRIPTION

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0021] See also Figure 1 As shown, the present invention provides a dynamic interferometer 10 based on AWG high-precision stable amplitude measurement, which can be used for wavefront shape detection of optical elements. The dynamic interferometer 10 includes a light source 11, a beam splitter 12, a first focusing lens 13, a light intensity sensor 14, an interference component 15, a detector 16 and a controller (not shown in the figure).

[0022] 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.

[0023] The beam splitter 12 and the interference assembly 15 are located on the optical path of the outgoing light beam of the light source 11, and the beam splitter 12 is located between the light source 11 and the interference assembly 15. The beam splitter 12 is used to split the incident light beam into a first light beam and a second light beam according to the distribution ratio. The first light beam passes through the first focusing lens 13 and is focused on the receiving surface of the light intensity sensor 14. Among them, the light intensity sensor 14 can be a photodiode. The light intensity sensor 14 is used to detect the light intensity of the first light beam, and send the light intensity of the first light beam to the controller, so that the controller can obtain the light intensity of the first light beam. The controller is used to adjust the light intensity of the light beam emitted by the light source 11 according to the difference between the light intensity of the first light beam detected by the light intensity sensor 14 and the set light intensity. Among them, the controller can be a PD controller. The controller can stabilize the amplitude of the light emitted by the light source 11, and can suppress the error caused by vibration, so as to achieve high-precision measurement of the surface 20 to be measured with stable frequency and amplitude.

[0024] The second light beam passes through the interference component 15. The interference component 15 includes a half wave plate 17, a polarization beam splitter 18 and a reflective mirror 19. The half wave plate 17 is arranged on the optical path from the beam splitter 12 to the polarization beam splitter 18. The half wave plate 17 is arranged between the beam splitter 12 and the polarization beam splitter 18. The second light beam passes through the half wave plate 17 and is incident on the polarization beam splitter 18, and is divided by the polarization beam splitter 18 into a reference light transmitted along the reference light path and a measurement light transmitted along the measurement light path. In this embodiment, the second light beam passes through the half wave plate 17 and is incident on the polarization beam splitter 18, and is divided by the polarization beam splitter 18 into two light beams with mutually perpendicular polarization directions, namely, P light as reference light transmitted along the reference light path and S light as measurement light transmitted along the measurement light path. The reflective mirror 19 is arranged in the reference light path, and is used to reflect the reference light back to the polarization beam splitter 18. The surface to be measured 20 is arranged in the measurement light path, and is used to reflect the measurement light back to the polarization beam splitter 18. The reference light and the measuring light reflected back to the polarization beam splitter 18 interfere with each other to form an image on the target surface of the detector 16 .

[0025] The dynamic interferometer 10 based on AWG high-precision stable amplitude measurement created by the present invention has the function of dynamically monitoring the amplitude of the light beam emitted by the light source 11. The controller can adjust the intensity of the light beam emitted by the light source 11 according to the difference between the light intensity of the first light beam detected by the light intensity sensor 14 and the set light intensity, thereby achieving the stabilization of the amplitude of the light beam emitted by the light source 11 and avoiding errors in the dynamic interferometer 10 during the detection process, thereby obtaining more accurate measurement results and realizing accurate measurement of the wavefront image of the surface 20 to be measured.

[0026] In one embodiment, the dynamic interferometer 10 based on AWG high-precision stable amplitude measurement further includes a first space mirror group 21, an arrayed waveguide grating 22, a second space mirror group 23 and a displacement mechanism. The first space mirror group 21 is arranged on the optical path from the light source 11 to the input port of the arrayed waveguide grating 22, and is used to transmit the light beam emitted by the light source 11 to the input port of the arrayed waveguide grating 22. In one embodiment, the first space mirror group 21 includes a first collimating lens 24 and a focusing lens 25, and the first collimating lens 24 is located between the light source 11 and the focusing lens 25. The focus of the first collimating lens 24 is aligned with the input port of the arrayed waveguide grating 22, and the first collimating lens 24 is used to collimate the light beam emitted by the light source 11. The focusing lens 25 is located on the optical path from the first collimating lens 24 to the input port of the arrayed waveguide grating 22. The focusing objective lens 25 is used to focus the light beam collimated by the first collimating lens 24 to the input port of the arrayed waveguide grating 22 , so that the first spatial mirror group 21 can transmit the light beam emitted by the light source 11 to the input port of the arrayed waveguide grating 22 .

[0027] The second space mirror group 23 is arranged on the optical path from the output port of the arrayed waveguide grating 22 to the beam splitter 12, and is used to transmit the light beam output from the output port of the arrayed waveguide grating 22 to the beam splitter 12. The second space mirror group 23 includes a beam expander 26 and a second collimating lens 27, and the beam expander 26 is located between the output port of the arrayed waveguide grating 22 and the second collimating lens 27. The focus of the beam expander 26 is aligned with any output port of the arrayed waveguide grating 22, and the focus of the beam expander 26 is aligned with one of the multiple output ports of the arrayed waveguide grating 22, so as to reduce the divergence of the light beam output from the output port of the arrayed waveguide grating 22. The second collimating lens 27 is located on the optical path from the beam expander 26 to the beam splitter 12, and can collimate the light beam passing through the beam expander 26 and transmit it to the beam splitter 12. So that the second space mirror group 23 can transmit the light beam output from the output port of the arrayed waveguide grating 22 to the beam splitter 12.

[0028] The arrayed waveguide grating (AWG) 22 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 22. The light source 11, the first space mirror group 21 and the arrayed waveguide grating 22 are all arranged in a displacement mechanism, and the displacement mechanism moves the above components so that different output ports of the arrayed waveguide grating 22 are aligned with the second space mirror group 23. The displacement mechanism moves the light source 11, the first space mirror group 21 and the arrayed waveguide grating 22, switches different channels of the arrayed waveguide grating 22, so that different output ports of the arrayed waveguide grating 22 are aligned with the second space mirror group 23. The light beam output from the output port of the arrayed waveguide grating 22 can enter the second space mirror group 23 and be transmitted to the interference component 15 through the second space mirror group 23. In one embodiment, the channel wavelength interval of the arrayed waveguide grating 22 ranges from 0.01nm to 0.1nm. In this embodiment, the channel wavelength interval of the arrayed waveguide grating 22 is 0.01 nm, and the wavelength resolution is high, so that the measurement accuracy of the wavefront shape detection of the optical element is higher. 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 2 The 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 22 is 0.01nm.

[0029] The dynamic interferometer 10 based on AWG high-precision stable amplitude 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 array waveguide grating 22, so that the wavefront image of the surface to be measured 20 can be measured more efficiently and accurately. The array waveguide grating 22 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 array waveguide grating 22, so that light beams of different wavelengths are output through different output channels of the array waveguide grating 22, so that each output port of the array waveguide grating 22 can output a light beam with a narrow line width and stable wavelength. And the light source 11, the first space mirror group 21 and the array waveguide grating 22 are arranged in a displacement mechanism, and the different output ports of the array waveguide grating 22 can be aligned with the second space mirror group 23 by cooperating with the displacement mechanism. Different output ports of the arrayed waveguide grating 22 can output light beams of different wavelengths, so that they can cooperate with the displacement mechanism to achieve multi-wavelength rapid measurement, so that the wavefront image of the surface to be measured 20 can be obtained with higher accuracy. At the same time, compared with the traditional dynamic interferometer, the dynamic interferometer 10 based on AWG high-precision stable amplitude 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.

[0030] In one embodiment, the displacement mechanism includes a driving component and a linkage component, wherein the driving component is connected to the linkage component and is used to drive the linkage component to work so as to move the light source 11, the first spatial mirror group 21 and the arrayed waveguide grating 22. The driving component can be a motor, a cylinder, etc. The linkage component adopts any of the following components: a chain drive component, a gear rack component, a lead screw nut component, etc.

[0031] In one embodiment, the interference assembly 15 further includes a first quarter wave plate 28 arranged in the reference light path, and the first quarter wave plate 28 is located between the polarization beam splitter 18 and the reflection mirror 19. The reference light passes through the first quarter wave plate 28 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 28 again and is reflected back to the polarization beam splitter 18. In this embodiment, the P polarized light as the reference light passes through the first quarter wave plate 28 and is converted into right-handed polarized light 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 28 again and is modulated into S polarized light and is reflected back to the polarization beam splitter 18.

[0032] In one embodiment, the interference assembly 15 further includes a second quarter wave plate 29 and a second focusing lens 30 arranged in the measuring optical path, the surface to be measured 20 is arranged in the measuring optical path, and the second focusing lens 30 is located between the second quarter wave plate 29 and the surface to be measured 20. The second focusing lens 30 is located in the optical path from the second quarter wave plate 29 to the surface to be measured 20. The measuring light passes through the second quarter wave plate 29 and the second focusing lens 30, is incident on the surface to be measured 20, is reflected from the surface to be measured 20, passes through the second focusing lens 30 and the second quarter wave plate 29 again, and is reflected back to the polarization beam splitter 18. In this embodiment, the S polarized light as the measuring light is converted into left-handed polarized light after passing through the second quarter wave plate 29, is incident on the surface to be measured 20 through the second focusing lens 30, is reflected from the surface to be measured 20, passes through the second focusing lens 30, and passes through the second quarter wave plate 29 again, is modulated into P polarized light, and returns to the polarization beam splitter 18.

[0033] In one embodiment, the interference assembly 15 further includes a third quarter wave plate 31, and the third quarter wave plate 31 is located between the polarization beam splitter 18 and the detector 16. The reference light and the measurement light are reflected back to the polarization beam splitter 18, and after passing through the third quarter wave plate 31, interference is formed to be imaged on the target surface of the detector 16. The reference light and the measurement light are reflected back to the polarization beam splitter 18, combined by the polarization beam splitter 18, and pass through the third quarter wave plate 31, so that the reference light and the measurement light interfere with each other to be imaged on the target surface of 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 combining, and pass through the third quarter wave plate 31, 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 to be imaged on the target surface of the detector 16.

[0034] In this embodiment, the first collimating lens 24, the focusing objective lens 25, the arrayed waveguide grating 22, the beam expander 26, the second collimating lens 27, the beam splitter 12, the half wave plate 17, the polarization beam splitter 18, the second quarter wave plate 29, the second focusing lens 30, and the surface to be measured 20 are arranged in sequence in the first straight line direction; the detector 16, the third quarter wave plate 31, the polarization beam splitter 18, the first quarter wave plate 28, and the reflecting mirror 19 are arranged in sequence in the second straight line direction, and the first straight line direction is perpendicular to the second straight line direction.

[0035] 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 22 are aligned with the second space mirror group 23, 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.

[0036] 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 stable amplitude 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.

[0037] The dynamic interferometer 10 based on AWG high-precision stable amplitude measurement created by the present invention has the characteristics of fast measurement, high-precision, high-accuracy detection, and insensitivity to vibration and airflow, 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.

[0038] 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.

[0039] 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 stable amplitude measurement, characterized in that: It includes a light source, a beam splitter, a first focusing lens, a light intensity sensor, an interference component, a detector and a controller; The light source is used to emit a light beam; the beam splitter and the interference component are located on the optical path of the outgoing light beam of the light source, and the beam splitter is located between the light source and the interference component; the beam splitter is used to split the incident light beam into a first light beam and a second light beam according to a distribution ratio; The first light beam passes through the first focusing lens and is focused on the receiving surface of the light intensity sensor, and the light intensity sensor is used to detect the light intensity of the first light beam; the controller is used to adjust the light intensity of the light beam emitted by the light source according to the difference between the light intensity of the first light beam detected by the light intensity sensor and the set light intensity; The interference component includes a half wave plate, a polarization beam splitter and a reflection mirror, wherein the half wave plate is arranged on the optical path from the beam splitter to the polarization beam splitter; the second light beam passes through the half wave plate and is incident on the polarization beam splitter, and is divided by the polarization beam splitter into a reference light transmitted along a reference light path and a measurement light transmitted along a measurement light path; the reflection mirror is arranged on the reference light path, and is used to reflect the reference light back to the polarization beam splitter; the surface to be measured is arranged on the measurement light path, and is used to reflect the measurement light back to the polarization beam splitter; the reference light and the measurement light reflected back to the polarization beam splitter interfere with each other, so as to be imaged on the target surface of the detector.

2. The dynamic interferometer based on AWG high-precision stable amplitude measurement according to claim 1, characterized in that: It also includes a first space mirror group, an arrayed waveguide grating, a second space mirror group and a displacement mechanism, 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 space mirror group is arranged on the optical path from the output port of the arrayed waveguide grating to the beam splitter, and is used to transmit the light beam output from the output port of the arrayed waveguide grating to the beam splitter; 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.

3. The dynamic interferometer based on AWG high-precision stable amplitude measurement according to claim 2, characterized in that: The channel wavelength interval of the arrayed waveguide grating ranges from 0.01 nm to 0.1 nm.

4. The dynamic interferometer based on AWG high-precision stable amplitude measurement according to claim 2, characterized in that: The displacement mechanism includes a driving component and a linkage component. The driving component is connected to the linkage component and is used to drive the linkage component to work so as to move the light source, the first spatial mirror group and the arrayed waveguide grating.

5. The dynamic interferometer based on AWG high-precision stable amplitude measurement according to claim 2, 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.

6. The dynamic interferometer based on AWG high-precision stable amplitude measurement according to claim 2, 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 output port of the arrayed waveguide grating. The second collimating lens is located on the optical path from the beam expander to the beam splitter.

7. The dynamic interferometer based on AWG high-precision stable amplitude 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.

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

9. The dynamic interferometer based on AWG high-precision stable amplitude 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 are reflected back to the polarization beam splitter and form interference after passing through the third quarter-wave plate, so as to be imaged on the target surface of the detector.

Images