Wavelength gating phase-shifting interference measurement system based on multi-wavelength narrow-band filtering metasurface

Abstract

The invention provides a wavelength gating phase-shifting interference measurement system based on a multi-wavelength narrow-band filtering metasurface, and relates to the technical field of optical detection. Comprising an incident light source, an optical interference system, a detector, a multi-wavelength narrow-band filtering metasurface and a computer module. The incident light source is used for simultaneously providing a plurality of test laser beams with different wavelengths; the optical interference system is used for enabling the test laser beams to generate interference; the multi-wavelength narrow-band filtering metasurface is arranged on a target surface of the detector, the multi-wavelength narrow-band filtering metasurface is used for gating a plurality of light beams with selected wavelengths, and the detector is used for collecting interferograms after optical interference of the light beams with different wavelengths; the detector is electrically connected with the computer module, and the computer module is used for resolving an interferogram; according to the invention, a new phase shift mechanism is provided for an optical interference measurement system, the detection efficiency of the interference measurement system is improved, the interference measurement system is simplified, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of optical system detection technology, and in particular to a wavelength-gated phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface. Background Art

[0002] For optical systems and optical components, the testing of their optical characteristics is related to the evaluation of the performance of optical components and optical systems. In addition, the testing is also indispensable in the process of optical system assembly and adjustment. For example, in an imaging system, it is usually necessary to test the phase difference and transfer function of the imaging lens to evaluate its imaging quality; in a laser system, in order to ensure the quality of the beam, it is usually necessary to strictly control the phase difference of optical components. In this process, the testing of the phase difference of its optical components or systems is crucial. It can be seen that the importance of optical characteristic testing for optical systems and optical components is self-evident.

[0003] At present, interferometric measurement systems are usually used to test the phase difference, transfer function, parallelism and other parameters of optical systems and optical elements. Current interferometric measurement systems usually use phase shifting methods to solve the interference pattern. The commonly used phase shifting methods are mainly mechanical phase shifting, wavefront tuning phase shifting, and polarization phase shifting. Among them, mechanical phase shifting cannot be measured dynamically and is greatly affected by external environmental vibrations, which is not conducive to high-precision measurement, especially for large-aperture interferometric measurement systems. This method is usually not used; wavefront tuning phase shifting cannot be measured dynamically, and it also requires a large, bulky and expensive wavelength-tuned laser light source, which is costly; polarization phase shifting has high requirements on the polarization state of the light beam and requires a special polarization camera. In addition, this method cannot measure birefringent crystals.

[0004] It can be seen that the traditional interferometric measurement system has the disadvantages of poor environmental adaptability, high cost, bulky system, high requirements for equipment such as light source and camera, and limited measurement scenarios. Summary of the invention

[0005] The purpose of the present invention is to solve the problems in the prior art of poor system environmental adaptability, high cost, bulky system, high requirements for equipment such as light source and camera, and limited measurement scenes.

[0006] To achieve the above object, the technical solution adopted by the present invention is: A wavelength-gated phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface comprises an incident light source, an optical interference system, a detector, a multi-wavelength narrow-band filtering metasurface and a computer module; the incident light source is used to simultaneously provide a plurality of test laser beams of different wavelengths; the optical interference system is used to cause interference of the test laser beams; the multi-wavelength narrow-band filtering metasurface is arranged on a target surface of the detector, the multi-wavelength narrow-band filtering metasurface is used to gate a plurality of selected wavelengths of light beams and suppress the passage of other wavelengths of light beams; the detector is used to collect interference patterns after optical interference of light beams of different wavelengths; the detector is electrically connected to the computer module, and the computer module is used to solve the interference patterns.

[0007] Preferably, the incident light source includes at least one broadband laser.

[0008] Preferably, the optical interference system can cause interference of the incident light beam, and the optical interference system is one of the radial shearing interference system, the lateral shearing interference system, the Michelson interference system, the Twyman-Green interference system, the Fizeau interference system, the Mach-Zehnder interference system, and the Fabry-Perot interference system, or it can be other forms of optical interference systems.

[0009] Preferably, the multi-wavelength narrow-band filtering metasurface includes several types of micro-nanostructure arrays, each of which can select a selected wavelength of incident light; several different micro-nanostructure arrays form a functional unit, which can realize the simultaneous selection of multiple selected wavelengths of incident light.

[0010] Preferably, the detector includes at least one camera, and the multi-wavelength narrow-band filtering metasurface is affixed to the target surface of each camera.

[0011] Compared with the prior art, the advantages of the present invention are: the wavelength-selected phase-shifting interferometry system based on the multi-wavelength narrow-band filtering metasurface solves the shortcomings of the traditional optical interferometry system, such as poor environmental adaptability, high cost, bulky and heavy system, high requirements for light source and camera and other equipment, and limited measurement scenes. The present invention introduces the metasurface into the interferometry system, and with the help of the flexible beam wavefront control capability of the metasurface, the detector can simultaneously collect interference patterns of multiple wavelengths, realizing a new phase shift mechanism. Compared with the traditional mechanical phase shift, wavelength tuning phase shift, and polarization phase shift, the phase shift mechanism greatly reduces the requirements of the optical interferometry system for equipment and the complexity of the interferometry system, thereby greatly reducing the weight, volume, and cost of the optical interferometry system, and greatly improving the environmental adaptability of the interferometry system. At the same time, it broadens the application scenarios of the interferometry system, making the interferometry system more cost-effective and the testing process more convenient and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of a wavelength-gated phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface of the present invention.

[0013] Figure 2 It is a schematic diagram of the structure of a multi-wavelength narrow-band filtering supersurface of a wavelength-selected phase-shifting interferometry measurement system based on the multi-wavelength narrow-band filtering supersurface of the present invention.

[0014] Figure 3 It is a schematic diagram of the working principle of a multi-wavelength narrow-band filtering supersurface in a wavelength-selected phase-shifting interferometry measurement system based on the multi-wavelength narrow-band filtering supersurface of the present invention.

[0015] Reference numerals

[0016] 1-incident light source, 2-optical interference system, 3-detector, 4-multi-wavelength narrow-band filtering metasurface, 5-computing module, 6-functional unit, 7-wavelength gating micro-nanostructure array, 8-micro-nanostructure. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] Example

[0019] Refer to the following Figures 1 to 3 To describe a wavelength-gated phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface provided according to some embodiments of the present invention.

[0020] Some embodiments of the present application provide a wavelength-selected phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface.

[0021] like Figure 1 As shown, the first embodiment of the present invention proposes a wavelength-selected phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface, including an optical interference system 2 arranged between an incident light source 1 and a detector 3, and a multi-wavelength narrow-band filtering metasurface 4 and a computing module 5 attached to the target surface of the detector 3. During testing, the light beam emitted by the incident light source 1 passes through the optical interference system 2 and then interferes with the light beam. The interfered light beam is selected by the multi-wavelength narrow-band filtering metasurface 4 and then reaches the detector 3. Finally, the computing module 5 solves the interference image collected by the detector 3, thereby obtaining the optical parameters of the optical system or component under test.

[0022] Specifically, the outgoing light beam of the incident light source 1 first passes through the optical interference system 2 and the measured element or system, wherein the interference system can be an interference system such as a radial shearing interference system, a lateral shearing interference system, a Michelson interference system, a Tyeman-Green interference system, a Fizeau interference system, a Mach-Zehnder interference system, a Fabry-Perot interference system, or other forms of interference systems; the measured element or system can be placed in front of the optical interference system 2, or after the optical interference system 2, or in the optical interference system 2; the light beam can first pass through the optical interference system 2 to separate the test light and the reference light, and then the test light passes through the measured element or system to interfere with the reference light, or it can first pass through the measured element, and then pass through the optical interference system 2 for splitting and then interfering; the interference can be in the form of double-beam interference or multi-beam interference.

[0023] It can be understood that double-beam or multi-beam interference will occur after the outgoing light beam of the incident light source 1 passes through the optical interference system 2 and the measured element or system; the detector 3 can detect and obtain the intensity distribution of the interference wavefront, and the wavefront phase and other information can be solved through the intensity distribution; the multi-wavelength narrow-band filtering metasurface 4 in front of the target surface of the detector 3 can perform multi-wavelength narrow-band filtering on the incident light beam, so that the detector 3 can obtain the interference wavefront intensity distribution of multiple wavelengths at the same time, and then the wavefront phase and other information in the interference pattern can be solved by the phase shifting method.

[0024] See also Figure 2 The multi-wavelength narrowband filtering metasurface 4 is composed of a plurality of functional units 6, each of which is composed of at least two wavelength-selecting micro-nanostructure arrays 7, and each wavelength-selecting micro-nanostructure array 7 can transmit light of a single selected wavelength within a certain line width, so that the functional unit 6 can simultaneously select light of multiple wavelengths at different spatial positions within a certain line width; in addition, the wavelength-selecting micro-nanostructure array 7 is composed of micro-nanostructures 8, and its narrowband filtering characteristics, that is, the specific wavelength of light that can pass through it within a certain line width, are determined by the geometric structure and material of the micro-nanostructure; in addition, the number of micro-nanostructures 8 contained in the wavelength-selecting micro-nanostructure array 7 can be one or more.

[0025] See also Figure 3 After the incident light beam passes through the wavelength gating of multiple wavelength gating micro-nanostructure arrays 7 in the functional unit 6, the light intensities of different wavelengths are detected by different adjacent pixel points on the detector, so that the entire camera target surface has the ability to simultaneously detect multiple wavelength interference images.

[0026] In some embodiments, the multi-wavelength narrow-band filtering metasurface 4 is provided with a plurality of functional units, and each functional unit has the same function.

[0027] In some embodiments, the multi-wavelength narrow-band filtering metasurface 4 is attached in front of the target surface of the detector 3, and each wavelength-selective micro-nanostructure array 7 covers at least one pixel; the multi-wavelength narrow-band filtering metasurface 4 is attached in front of the target surface of the detector 3 by sticking the processed multi-wavelength narrow-band filtering metasurface 4 on the target surface of the detector 3, or by directly processing the multi-wavelength narrow-band filtering metasurface 4 in front of the target surface of the detector 3; in a specific embodiment, the multi-wavelength narrow-band filtering metasurface 4 is attached in front of the target surface of the detector 3 by means of a patch, and the side processed with the micro-nanostructure faces the target surface of the detector 3.

[0028] In some embodiments, a functional unit 6 includes multiple wavelength-selectable micro-nanostructure arrays 7, and the geometry and material properties of the micro-nanostructures in each wavelength-selectable micro-nanostructure array 7 are different, and the wavelengths that can be selected are also different; in a specific embodiment, a functional unit 6 includes 4 wavelength-selectable micro-nanostructure arrays 7, which can simultaneously select 4 wavelengths of incident light to achieve a four-step phase shift.

[0029] In some embodiments, the same wavelength-gating micro-nanostructure array 7 is composed of a plurality of identical micro-nanostructures 8, wherein the micro-nanostructure 8 can be of any shape and size, such as a regular shape such as a rectangle, a trapezoid, a triangle, a polygon, or an irregular shape. In a specific embodiment, the micro-nanostructures 8 of the four wavelength-gating micro-nanostructure arrays 7 are rectangular, triangular, circular, and pentagonal structures, respectively.

[0030] In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0031] Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A wavelength-gated phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface, characterized in that: It comprises an incident light source, an optical interference system, a detector, a multi-wavelength narrow-band filtering metasurface and a computer module; the incident light source is used to simultaneously provide a plurality of test laser beams of different wavelengths; the optical interference system is used to cause interference of the test laser beams; the multi-wavelength narrow-band filtering metasurface is arranged on the target surface of the detector, and the multi-wavelength narrow-band filtering metasurface is used to select a plurality of selected wavelengths of light beams and suppress the passage of other wavelengths of light beams; the detector is used to collect interference patterns after optical interference of light beams of different wavelengths; the detector is electrically connected to the computer module, and the computer module is used to solve the interference pattern.

2. The wavelength-gated phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface according to claim 1 is characterized in that: The incident light source includes at least one broad spectrum laser.

3. The wavelength-gated phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface according to claim 1 is characterized in that: The optical interference system can cause interference of the incident light beam, and the optical interference system is one of a radial shearing interference system, a lateral shearing interference system, a Michelson interference system, a Twyman-Green interference system, a Fizeau interference system, a Mach-Zehnder interference system, and a Fabry-Perot interference system.

4. The wavelength-gated phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface according to claim 1, characterized in that: The multi-wavelength narrow-band filtering metasurface includes several kinds of micro-nanostructure arrays, each of which can select a selected wavelength of incident light; several different micro-nanostructure arrays form a functional unit for realizing simultaneous selection of multiple selected wavelengths of incident light.

5. The wavelength-gated phase-shifting interferometry measurement system based on a multi-wavelength narrow-band filtering metasurface according to claim 1, characterized in that: The detector includes at least one camera, and the multi-wavelength narrow-band filtering metasurface is attached to the target surface of each camera.

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