Grating diffraction efficiency detection system and detection method thereof

Abstract

The application discloses a grating diffraction efficiency detection system and a detection method thereof, which comprises a bearing platform, a sample platform rotatably arranged above the bearing platform, an incident assembly, a lens assembly, a first imaging lens, a beam splitter, a first photoelectric detection device, a second photoelectric detection device and a second imaging lens. The incident assembly comprises a light source aligned with the sample platform, a beam modulator arranged on an outgoing light path of the light source and a polarization modulator arranged on an outgoing light path of the beam modulator. The lens assembly is aligned with a micro-nano grating to be detected and a diffraction beam thereof. The first imaging lens is arranged on an outgoing light path of the lens assembly. The beam splitter is arranged on an outgoing light path of the first imaging lens. The first photoelectric detection device is arranged on a reflected light path of the beam splitter. The second imaging lens is arranged on a transmitted light path of the beam splitter. The second photoelectric detection device is arranged on an outgoing light path of the second imaging lens. The application solves the problem that a traditional macroscopic grating diffraction efficiency measurement scheme cannot detect the diffraction efficiency of a micro-nano scale diffraction grating.

Description

Technical Field

[0001] This invention relates to the field of grating inspection equipment technology, and specifically to a grating diffraction efficiency detection system and its detection method. Background Technology

[0002] With the rapid development of the information age, virtual reality (including augmented reality and mixed reality) has become a cutting-edge development direction of the next generation of information technology. At the same time, micro-nano photonics has also made tremendous leaps forward. Combining micro-nano photonics with virtual reality, and then manipulating and controlling light waves at the micro-nano scale to achieve the thinner, more integrated, and miniaturized nature of virtual reality devices, has become a core issue. Micro-nano scale diffraction gratings are one of the most representative optical components, widely used in important forward-looking optical modules such as diffractive waveguides, spatial light modulators, and lidar.

[0003] Unlike the etched gratings in traditional spectrometers and spectrophotometers, micro / nano-scale diffraction gratings have morphological characteristics on the scale of tens to hundreds of nanometers and can be fabricated using electron beam etching, photolithography, and nanoimprint lithography. With further advancements in fabrication processes and in-depth design research, micro / nano-scale diffraction gratings have undergone many revolutionary changes. The focus has shifted from periodic variations in a single morphology to gratings with identical periods on a macroscopic scale, but with microscopic morphological designs, allowing for different diffraction efficiency distributions in different microscopic regions of a grating to achieve optimal light wave manipulation. Because the regions with identical morphologies on the microscopic scale of the grating are on the scale of tens of micrometers, traditional macroscopic grating diffraction efficiency measurement schemes are no longer applicable, and related technologies are currently lacking both domestically and internationally. Traditional macroscopic grating diffraction efficiency measurement schemes cannot detect the diffraction efficiency of micro / nano-scale diffraction gratings in their microscopic regions.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, a grating diffraction efficiency detection system and method are provided to solve the problem that traditional macroscopic grating diffraction efficiency measurement schemes cannot detect the diffraction efficiency of micro- and nano-scale diffraction gratings in their microscopic regions.

[0006] To achieve the above objectives, a grating diffraction efficiency detection system is provided, comprising:

[0007] A support platform, on which a sample stage for mounting a micro / nano grating to be tested is rotatably mounted;

[0008] The incident component includes a light source aligned with the sample stage, a beam modulator disposed in the light output path of the light source, and a polarization modulator disposed in the light output path of the beam modulator.

[0009] A lens assembly is aligned with the micro / nano grating under test and its diffraction beam.

[0010] A first imaging lens is disposed in the light output path of the lens assembly;

[0011] A beam splitter is disposed in the light output path of the first imaging lens;

[0012] A first photoelectric detection device for acquiring an image of the micro / nano grating under test is disposed on the reflected light path of the beam splitter;

[0013] A second photoelectric detection device is used to acquire the image of the micro-nano grating under test through the optical Fourier surface of the lens assembly. A second imaging lens is provided on the transmission optical path of the beam splitter, and the second photoelectric detection device is provided on the output optical path of the second imaging lens.

[0014] Furthermore, the incident component is rotatably mounted on the support platform with the area to be detected of the micro / nano grating under test as the center.

[0015] Furthermore, it also includes a third photoelectric detection device for acquiring the zero-order diffraction signal of the micro-nano grating under test. The third photoelectric detection device is aligned with the reflected beam of the micro-nano grating under test, and a beam collector is disposed between the third photoelectric detection device and the micro-nano grating under test.

[0016] Furthermore, the first photoelectric detection device, the second photoelectric detection device, and the third photoelectric detection device are each any one of a CCD camera, a spectrophotometer, and a spectrometer.

[0017] Furthermore, the lens assembly is an objective lens.

[0018] Furthermore, the lens assembly is a plan-achromatic large numerical aperture objective lens.

[0019] This invention provides a detection method for a grating diffraction efficiency detection system, comprising the following steps:

[0020] The micro / nano grating to be tested is mounted on the sample stage above the support.

[0021] Rotate the sample stage so that the micro / nano grating under test is aligned with the incident component and the lens component is aligned with the micro / nano grating under test and its diffracted beam;

[0022] Turn on the light source of the incident assembly;

[0023] After the light source outputs a stable beam, the stable beam is shaped by the beam modulator of the incident component to make the stable beam highly collimated, uniformly distributed in intensity, and to control the diameter of the stable beam.

[0024] After the stable beam is shaped, the polarization modulator of the incident component adjusts the shaped stable beam to form an incident beam with a specific polarization state.

[0025] The incident beam is incident on the micro-nano grating under test at a preset incident angle. After being diffracted by the micro-nano grating, the lens assembly collects the diffracted beam of the micro-nano grating.

[0026] The first photoelectric detection device acquires an image of the micro-nano grating under test via the reflected light path of the first imaging lens and the beam splitter;

[0027] When the image of the micro / nano grating under test is clear, the second photoelectric detection device acquires the image of the micro / nano grating under test through the optical Fourier surface of the lens assembly via the transmission optical path of the first imaging lens and the beam splitter in one go, thereby obtaining the diffraction intensity of the micro / nano grating under test as a function of the diffraction angle (θ). dif Distribution of wavelength (λ) and wavelength (λ) dif (θ) dif ,λ);

[0028] The micro / nano grating under test is removed from the sample stage, and the second photoelectric detection device collects the incident light beam to obtain the intensity I of the incident light beam. source ;

[0029] Based on the distribution of diffraction intensity of the micro / nano grating under test with diffraction angle and wavelength I dif (θ) dif , λ) and the intensity I of the incident beam source The diffraction efficiency of the micro / nano grating under test is calculated.

[0030] The beneficial effects of this invention are that the grating diffraction efficiency detection system and method of this invention are advantageous for the rapid and efficient detection of the diffraction efficiency of local micro-regions of micro / nano-scale diffraction gratings. When equipped with an area array spectrometer, the distribution of diffraction efficiency as a function of angle and wavelength in the local micro-region of the micro / nano-grating under test can be obtained with only one spectral acquisition. The principle of the grating diffraction efficiency detection system and method of this invention differs from that of traditional grating diffraction efficiency detection methods. This invention uses a second photoelectric detection device to detect the image of the optical Fourier surface of the micro / nano-grating under test through the lens assembly, thus eliminating the need for mechanical scanning at different diffraction angles; diffraction information for all diffraction angles can be obtained in a single imaging operation. Furthermore, the first photoelectric detection device acquires information about the micro / nano-grating sample under test in real space, enabling real-time observation and determination of the specific micro-region of the micro / nano-grating sample measured by the second photoelectric detection device. Attached Figure Description

[0031] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0032] Figure 1 This is a schematic diagram of the structure of the grating diffraction efficiency detection system according to an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram of the transmission mode of the incident component according to an embodiment of the present invention.

[0034] Figure 3 This is a schematic diagram of the layout of the third photoelectric detection device according to an embodiment of the present invention.

[0035] Figure 4 This is a side view of the incident component structure according to an embodiment of the present invention.

[0036] Figure 5 This is a side view of the transmission mode structure of the incident component according to an embodiment of the present invention.

[0037] Figure 6 This is a schematic diagram of the diffraction efficiency distribution of a one-dimensional chromium nanograting according to an embodiment of the present invention.

[0038] Figure 7 This is a schematic diagram showing the distribution of the diffraction efficiency of a one-dimensional chromium nanograting as a function of the diffraction angle in an embodiment of the present invention.

[0039] Figure 8 This is a schematic diagram showing the distribution of the diffraction efficiency of a one-dimensional chromium nanograting as a function of wavelength, according to an embodiment of the present invention.

[0040] Figure 9 This is a schematic diagram illustrating the distribution of diffraction efficiency of a commercial blazed grating as a function of angle and wavelength, according to an embodiment of the present invention. Detailed Implementation

[0041] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0043] Reference Figures 1 to 7 As shown, the present invention provides a grating diffraction efficiency detection system, comprising: a platform 1, an incident component 2, a lens component 3, a first imaging lens 4, a beam splitter 5, a first photoelectric detection device 6, and a second photoelectric detection device 7.

[0044] The support platform provides a stable working environment for the entire testing system. A sample stage 11 is rotatably mounted on top of the support platform 1. The sample stage 11 is used to mount the micro / nano grating to be tested.

[0045] In this embodiment, the micro / nano grating under test is a micro / nano scale diffraction grating. Specifically, the sample stage 11 is disk-shaped. A drive motor 13 is mounted below the sample stage. The output end of the drive motor is coaxially connected to the sample stage. The drive motor is mounted on a support platform and drives the sample stage to rotate. Preferably, a height adjustment cylinder is mounted on the support platform and supported by the drive motor. The drive motor is fixed to the telescopic end of the height adjustment cylinder. The fixed end of the height adjustment cylinder is located on the support platform.

[0046] The incident component 2 includes a light source 21, a beam modulator 22, and a polarization modulator 23. The light source 21 is aligned with the sample stage 11. The beam modulator 22 is disposed in the output light path of the light source 21. The polarization modulator 23 is disposed in the output light path of the beam modulator 22.

[0047] The light source is a monochromatic laser source or a broadband light source, and the power output of the light source needs to be highly stable.

[0048] A beam modulator is a beam control device used to shape an incident light source, resulting in high collimation of the output light source, uniform intensity distribution, and control over the beam diameter.

[0049] A polarization modulator is a polarizer, or a combination of a polarizer and a waveplate, used to adjust the polarization of an incident beam.

[0050] In some embodiments, the incident component 2 is rotatably mounted on the support 1 with the area to be detected of the micro / nano grating under test as the center. For details, see the appendix. Figure 4 and Figure 5A lifting cylinder 12 is installed on the support platform. The incident component is installed on the lifting cylinder with an adjustable angle. Specifically, the incident component is set along the preset incident direction of the light from the micro-nano grating to be measured. The middle part of the incident component is hinged to the telescopic end of the lifting cylinder via a hinge assembly. The hinge assembly can adjust the pitch angle of the incident component, so that the incident component is set along the preset incident angle.

[0051] Lens assembly 3 is aligned with the micro / nano grating to be measured and its diffraction beam.

[0052] The first imaging lens 4 is disposed on the light output path of the lens assembly 3.

[0053] Beam splitter 5 is positioned on the light output path of the first imaging lens 4.

[0054] The first photoelectric detection device 6 is disposed on the reflected light path of the beam splitter 5. The first photoelectric detection device 6 is used to acquire the image of the micro / nano grating under test.

[0055] A second imaging lens 71 is disposed on the transmission light path of the beam splitter 5. A second photoelectric detection device 7 is disposed on the output light path of the second imaging lens 71. The second photoelectric detection device 7 is used to acquire the image of the micro-nano grating under test through the optical Fourier surface of the lens assembly 3.

[0056] A lens assembly is a microscope objective or a lens group functionally equivalent to an objective. Lens assemblies are used to magnify microscopic regions and perform optical Fourier transforms to convert real space to momentum space.

[0057] In this embodiment, lens assembly 3 is an objective lens. Lens assembly 3 is a plan-achromatic large numerical aperture objective lens.

[0058] The beam splitter can be a beam-splitting cube or a beam-splitting plate. In this invention, the corresponding position of the beam splitter in the entire system can also be replaced by a reflector that can cut into or out the optical path.

[0059] The first photoelectric detection device, the second photoelectric detection device, and the third photoelectric detection device 8 are any one of a CCD (charge-coupled device) camera, a spectrophotometer, and a spectrometer, respectively. The spectrometer is an area array spectrometer.

[0060] In this invention, the incident component is rotatably mounted on a support platform with the area to be tested of the micro / nano grating as the center. This allows for the detection of the diffraction efficiency of the grating's micro-region at a specific incident angle. With a fixed incident angle, the light source, beam modulator, and polarization modulator are integrated into the same flip-up incident component to achieve incident angles of different magnitudes. (See attached figures.) Figure 5As shown, the incident component can be flipped below the sample stage to expand the detection capability of diffraction efficiency. This allows for the detection of diffraction efficiency in both reflective and transmissive grating samples. At different excitation angles, the diffraction efficiency of the grating exhibits rich optical information as a function of wavelength and diffraction angle, enabling comprehensive and quantitative measurement and analysis of the diffraction efficiency in the low-light region of the grating.

[0061] Combined Figure 3 As shown, in some embodiments, the grating diffraction efficiency detection system of the present invention further includes a third photoelectric detection device 8. The third photoelectric detection device 8 is used to collect the zero-order diffraction signal of the micro-nano grating under test. The third photoelectric detection device 8 is aligned with the reflected beam of the micro-nano grating under test. A beam collector 81 is disposed between the third photoelectric detection device 8 and the micro-nano grating under test.

[0062] The zero-order diffraction signal is detected by passing the incident beam along its reflection direction through a beam collector and a third photoelectric detection device. The beam collector is a beam-converging element, such as a lens or lens group. The third photoelectric detection device is a detector with light energy sensing capabilities, such as a CCD camera, spectrophotometer, or spectrometer.

[0063] When the incident light source is a single wavelength, the third photoelectric detection device can use a regular CCD camera to detect the reflection intensity; when the light source is a broadband light source, the third photoelectric detection device needs to use a spectrophotometer or spectrometer to achieve wavelength-resolved reflection spectrum detection.

[0064] This invention provides a detection method for a grating diffraction efficiency detection system, comprising the following steps:

[0065] S1: The micro / nano grating to be tested is mounted on the sample stage 11 above the support 1.

[0066] S2: Rotate the sample stage 11 so that the micro-nano grating to be tested is aligned with the incident component 2 and the lens component 3 is aligned with the micro-nano grating to be tested and its diffracted beam.

[0067] S3: Turn on the light source 21 of the incident component.

[0068] S4: After the light source 21 outputs a stable beam, the stable beam is shaped by the beam modulator 22 of the incident component 2 to make the stable beam highly collimated, uniform in intensity distribution, and control the diameter of the stable beam.

[0069] S5: After the stable beam is shaped, the polarization modulator 23 of the incident component 2 adjusts the shaped stable beam to form an incident beam with a specific polarization state.

[0070] S6: The incident beam is incident on the micro-nano grating to be tested at a preset incident angle. After diffraction by the micro-nano grating, the lens assembly 3 collects the diffracted beam of the micro-nano grating.

[0071] S7: The first photoelectric detection device 6 collects the image of the micro-nano grating under test through the reflected light path of the first imaging lens 4 and the beam splitter 5.

[0072] S8: When the image of the micro / nano grating under test is clear, the second photoelectric detection device 7 acquires the image of the micro / nano grating under test through the optical Fourier surface of the lens assembly 3 via the transmission optical path of the first imaging lens 4 and the beam splitter 5 to obtain the diffraction intensity of the micro / nano grating under test as a function of the diffraction angle (θ) of the incident beam. dif Distribution of wavelength (λ) and wavelength (λ) dif (θ) dif ,λ).

[0073] S9: Move the micro / nano grating to be tested out of the sample stage 11 and rotate the incident component to the transmission position below the sample stage. The second photoelectric detection device 7 collects the incident beam to obtain the intensity I of the incident beam. source .

[0074] S10: Distribution of diffraction intensity as a function of angle and wavelength based on the micro / nano grating under test. dif (θ dif ,λ) and the intensity I of the incident beam source The diffraction efficiency of the micro / nano grating under test is calculated.

[0075] The light wave generated by the light source undergoes beam shape and polarization modulation by the beam modulator and deflection modulator of the incident component, and then enters the light at a certain incident angle θ. in The light is incident on the micro / nano diffraction grating to be measured, placed on the sample stage. After diffraction by the grating, the diffraction signals at different angles generated by the grating structure in the micro-region are collected by the lens assembly and converged at different spatial positions on the back focal plane 30 (optical Fourier surface or momentum space plane) of the lens assembly. On one hand, after passing through the first imaging lens and beam splitter, the image of the micro-region of the grating will be acquired by the first photodetector to determine the position of the micro-region of the grating being measured; on the other hand, the back focal plane is imaged onto the second photodetector by the first and second imaging lenses. The first and second imaging lenses are plano-convex lenses.

[0076] If the light source is a monochromatic light source or a light source with continuously adjustable wavelength, the second photoelectric detection device can use an ordinary detector; if the light source is a broadband light source, the second photoelectric detection device needs to be changed to a spectrophotometer or spectrometer to achieve the angle and wavelength resolution of grating diffraction, that is, the distribution of diffraction efficiency with wavelength and angle.

[0077] To further illustrate the application effects of the grating diffraction efficiency detection system and method of the present invention, the following embodiments are provided for detailed explanation.

[0078] Example 1

[0079] In this embodiment, the national first-class standard material "one-dimensional chromium nanograting material" (number GBW13982) prepared by Tongji University is used as an example. The period of this one-dimensional chromium nanograting is a = 212.8 nm. According to the diffraction formula, the diffraction information of this grating is in the short-wavelength range. Specifically, taking θ... in =70° incident angle, θ dif The diffraction signal is scanned and received within the range of -55° to 55°, and the polarization selection is the s-polarization direction.

[0080] Specifically, the light source is a white light source. The first photoelectric detection device is a CCD camera, and the second photoelectric detection device is an area array spectrometer.

[0081] According to the attached diagram Figure 3 Following the sequence, place the optical components, turn on the light source for preheating, and ensure the output power of the light source is stable. Place the grating to be tested onto the sample stage, and adjust the beam modulator so that the incident beam is at an angle θ. in =70° to the grating under test, and at the same time the angle of the beam collector makes θ dif =-θ in The height of the sample stage is then adjusted to maximize the energy of the incident light reflected from the grating sample to the beam modulator and detected by the third photodetector, thus determining the sample surface of the grating. Simultaneously, after the grating region is clearly visible in the CCD camera, the grating diffraction signal is acquired using an area array spectrometer. By rotating the sample stage to align the grating diffraction orientation with the slit of the area array spectrometer, the distribution of diffraction intensity as a function of angle and wavelength in this micro-region can be obtained with a single spectral acquisition. dif (θ dif (λ). During the measurement process, light source acquisition is required. Specifically, after the grating sample to be measured is moved out of the Yang platform, intensity acquisition (I) is performed. source Then the diffraction efficiency of the micro-region of the grating can be obtained, as shown in the following formula:

[0082]

[0083] Finally, the distribution of the diffraction efficiency of the one-dimensional chromium nanograting as a function of angle and wavelength is shown in the attached figure. Figures 6 to 8 As shown.

[0084] Example 2

[0085] In this embodiment, the micro / nano grating under test is a commercially available blazed grating. Combined with... Figure 2 , Figure 5and Figure 9 As shown, to achieve transmissive angular illumination, the incident beam is incident on a commercial blazed grating at 0 degrees. After diffraction by the grating, diffraction signals of different wavelengths and orders propagate at different angles and are collected by a lens assembly, converging at different spatial positions on the back focal plane of the lens assembly. A high-resolution area array spectrometer (i.e., the second photoelectric detection device) is used to acquire the diffraction signals. The slit of the area array spectrometer needs to coincide with the diffraction orientation of the grating under test to obtain accurate diffraction efficiency. The measurement results are as follows... Figure 9 As shown, multiple diffraction orders exist within the measured wavelength range.

[0086] Specifically, refer to the attached diagram. Figure 2 Following the sequence, place the optical components, turn on the light source for preheating, and ensure stable light source output power. Place the grating to be tested onto the sample stage, and adjust the sample stage so that the incident beam is at an angle θ. in The sample stage is adjusted so that the grating region can be clearly seen in the first photoelectric detection device (camera) at a 0° angle. The second photoelectric detection device (area array spectrometer) is then used to acquire the grating diffraction signal. By rotating the sample stage, the orientation of the grating diffraction is aligned with the slit of the area array spectrometer. Only one spectral acquisition is needed to obtain the distribution of the diffraction intensity of the grating in this microscopic region as a function of angle and wavelength. dif (θ dif It is important to note that light source acquisition is required during the measurement process. The intensity of the light source is measured by removing the sample and collecting the intensity I. source Then the diffraction efficiency of the micro-region of the grating can be obtained.

[0087]

[0088] The grating diffraction efficiency detection system and method of this invention are beneficial for the rapid and efficient detection of diffraction efficiency in local micro-regions of micro / nano-scale diffraction gratings. With a planar array spectrometer, the distribution of diffraction efficiency as a function of angle and wavelength in a local micro-region of the micro / nano-scale grating under test can be obtained with a single spectral acquisition. Simultaneously, it supports highly flexible adjustment of the incident angle and is compatible with both transmission and reflection grating samples. The grating diffraction efficiency detection system based on micro-area angle-resolved imaging of this invention, combined with an automated wafer scanning sample stage, can also provide efficient analytical methods and standards for the morphology measurement, quality control, and classification of diffraction gratings in wafer-level diffraction waveguides, contributing to the development of virtual reality, augmented reality, mixed reality, and micro / nano photonics fields in my country.

[0089] Unlike traditional methods for detecting grating diffraction efficiency, this invention records the optical Fourier surface of the lens assembly using a second photoelectric detection device. This eliminates the need for scanning at different angles; diffraction information for all diffraction angles can be obtained in a single image. Since different positions on the optical Fourier surface correspond to different angles of light, only a single image is required. Furthermore, a real-space sample is acquired using a first photoelectric detection device to allow for real-time observation and determination of the microscopic region of the grating sample being measured by the second photoelectric detection device.

[0090] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A grating diffraction efficiency detection system, characterized in that, include: A support platform, on which a sample stage for mounting a micro / nano grating to be tested is rotatably mounted; The incident component includes a light source aligned with the sample stage, a beam modulator disposed in the light output path of the light source, and a polarization modulator disposed in the light output path of the beam modulator. A lens assembly is aligned with the micro / nano grating under test and its diffraction beam. A first imaging lens is disposed in the light output path of the lens assembly; A beam splitter is disposed in the light output path of the first imaging lens; A first photoelectric detection device for acquiring an image of the micro / nano grating under test is disposed on the reflected light path of the beam splitter; A second photoelectric detection device is used to acquire the image of the micro-nano grating under test through the optical Fourier surface of the lens assembly. A second imaging lens is provided in the transmission optical path of the beam splitter, and the second photoelectric detection device is provided in the output optical path of the second imaging lens. When the image of the micro-nano grating under test is clear, the second photoelectric detection device acquires the image of the optical Fourier surface of the micro-nano grating under test through the transmission optical path of the first imaging lens and the beam splitter in one go to obtain the distribution of the diffraction intensity of the micro-nano grating under test as a function of the diffraction angle and wavelength of the incident beam.

2. The grating diffraction efficiency detection system according to claim 1, characterized in that, The incident component is rotatably mounted on the support platform with the area to be tested of the micro / nano grating as the center.

3. The grating diffraction efficiency detection system according to claim 1, characterized in that, It also includes a third photoelectric detection device for acquiring the zero-order diffraction signal of the micro-nano grating under test. The third photoelectric detection device is aligned with the reflected beam of the micro-nano grating under test, and a beam collector is disposed between the third photoelectric detection device and the micro-nano grating under test.

4. The grating diffraction efficiency detection system according to claim 3, characterized in that, The first photoelectric detection device, the second photoelectric detection device, and the third photoelectric detection device are each any one of a CCD camera, a spectrophotometer, and a spectrometer.

5. The grating diffraction efficiency detection system according to claim 1, characterized in that, The lens assembly is an objective lens.

6. The grating diffraction efficiency detection system according to claim 5, characterized in that, The lens assembly is a plan-achromatic high numerical aperture objective lens.

7. A detection method for a grating diffraction efficiency detection system as described in any one of claims 1 to 6, characterized in that, Includes the following steps: The micro / nano grating to be tested is mounted on the sample stage above the support. Rotate the sample stage so that the micro / nano grating under test is aligned with the incident component and the lens component is aligned with the micro / nano grating under test and its diffraction beam. Turn on the light source of the incident assembly; After the light source outputs a stable beam, the stable beam is shaped by the beam modulator of the incident component to make the stable beam highly collimated, uniformly distributed in intensity, and to control the diameter of the stable beam. After the stable beam is shaped, the polarization modulator of the incident component adjusts the shaped stable beam to form an incident beam with a specific polarization state. The incident beam is incident on the micro-nano grating under test at a preset incident angle. After being diffracted by the micro-nano grating, the lens assembly collects the diffracted beam of the micro-nano grating. The first photoelectric detection device acquires the image of the micro / nano grating under test via the reflected light path of the first imaging lens and beam splitter; When the image of the micro-nano grating under test is clear, the second photoelectric detection device acquires the image of the micro-nano grating under test through the optical Fourier surface of the lens assembly via the transmission optical path of the first imaging lens and the beam splitter to obtain the diffraction intensity of the micro-nano grating under test as a function of the diffraction angle. θ dif ) and wavelength ( λ Distribution of ) I dif (θ) dif ,λ) ; The micro / nano grating under test is removed from the sample stage, and the second photoelectric detection device collects the incident light beam to obtain the intensity of the incident light beam. I source ; Based on the distribution of diffraction intensity of the micro / nano grating under test with diffraction angle and wavelength I dif (θ) dif ,λ) and the intensity of the incident beam I source The diffraction efficiency of the micro / nano grating under test is calculated.

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