DOE optical performance test system and method based on LabVIEW

Abstract

The invention relates to a DOE optical performance test system and method based on LabVIEW. The DOE optical performance test system based on LabVIEW comprises a laser light source driving module, a light source power detection module, a DOE power detection module and a LabVIEW software platform, and the laser light source driving module comprises a wavelength tunable laser, a neutral density optical filter, a one-dimensional electric displacement table and a beam splitter. The light source power detection module comprises a first photoelectric detector and a first digital source meter, the DOE power detection module comprises a DOE, a three-dimensional electric displacement table, a second photoelectric detector and a second digital source meter, and the LabVIEW software platform comprises a processor in which LabVIEW software is stored.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical measurement, and particularly relates to a DOE optical performance test system and method based on LabVIEW. Background Art

[0002] Diffractive optical elements (DOEs) are a class of advanced optical elements that work based on the principle of light diffraction. By precisely manufacturing tiny periodic structures on a transparent substrate, they control the propagation path of light waves. Compared with traditional refractive optical elements, DOEs have the characteristics of being thin, light, and compact, with flexible designs and easy for mass production. Therefore, they play an increasingly crucial role in the design of modern optical systems. In imaging systems, DOEs are used to perform complex optical functions such as wavefront correction, beam shaping, and aberration correction; in display technologies, they are used to improve the resolution and contrast of display devices; in the field of optical communication, DOEs are used for wavelength division multiplexing and precise routing of optical signals. In addition, DOEs also play important roles in many fields such as biomedical imaging, optical data processing, and security systems.

[0003] Diffraction efficiency is a key indicator for measuring the optical performance of DOEs, which reflects the conversion efficiency of DOEs for light energy at a specific wavelength. The level of diffraction efficiency directly affects the imaging quality, light energy utilization rate, and overall performance of optical systems. Therefore, the accurate measurement and analysis of the diffraction efficiency of DOEs are crucial for their design and application.

[0004] Traditional DOE diffraction efficiency detection methods have disadvantages such as long time consumption, low efficiency, and difficulty in meeting the requirements of rapid and batch testing. Existing DOE diffraction efficiency detection systems developed by further improving traditional DOE diffraction efficiency detection methods can, to a certain extent, meet the test requirements for the optical performance of DOEs, but they have low popularity, cannot fully adapt to the test requirements of different types of DOEs, and are difficult to maintain stability and accuracy under changing working conditions.

[0005] Therefore, developing a fully automated detection system that can more efficiently, comprehensively, and accurately evaluate the optical performance of DOEs will help improve the quality control level of DOE products and promote the innovation and development of related optical technologies. Summary of the Invention

[0006] The object of the present invention is to provide a DOE optical performance test system and method based on LabVIEW, which can achieve rapid, accurate, and fully automated measurement of the optical diffraction efficiency of DOEs under different test conditions.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] The first aspect of the present invention provides a DOE optical performance testing system based on LabVIEW, which includes a laser light source driving module, a light source power detection module, a DOE power detection module, and a LabVIEW software platform. Among them, the laser light source driving module includes a wavelength tunable laser, a neutral density filter, a one-dimensional electric displacement stage, and a beam splitter. The neutral density filter and the one-dimensional electric displacement stage are located between the wavelength tunable laser and the beam splitter, and the neutral density filter is arranged on the one-dimensional electric displacement stage. The light source power detection module includes a first photodetector and a first digital source meter. The receiving end of the first photodetector faces the reflecting surface of the beam splitter, and the first digital source meter is connected to the first photodetector. The DOE power detection module includes a DOE, a three-dimensional electric displacement stage, a second photodetector, and a second digital source meter. The DOE is located on the side where the transmitting surface of the beam splitter is located. The second photodetector is arranged on the three-dimensional electric displacement stage. The receiving end of the second photodetector faces the DOE, and the second digital source meter is connected to the second photodetector. The LabVIEW software platform is used to control the movement of the one-dimensional electric displacement stage and the three-dimensional electric displacement stage, and is used to process the data from the first digital source meter and the second digital source meter to obtain the optical diffraction efficiency of the DOE.

[0009] In the present invention, the energy of the test beam is adjusted by the neutral density filter, so that the power of the incident light on the DOE meets the requirements of the DOE and the detection range of the photodetector. Therefore, the power requirement for the laser light source is relatively low, and the DOE diffraction efficiency test under different laser energies can be realized. The energy of the test beam is accurately adjusted by the one-dimensional electric displacement stage and the LabVIEW software, and the diffraction spot detected by the second photodetector is accurately adjusted by the three-dimensional electric displacement stage and the LabVIEW software, so that the diffraction light of different diffraction orders can be detected quickly and continuously. The DOE optical performance testing system of the present invention can automatically adjust the test light power and test sites for different DOEs, realizing more efficient, fast, and accurate fully automated detection.

[0010] In an embodiment of the present invention, the connection line between the first photodetector and the beam splitter is perpendicular to the connection line between the second photodetector and the beam splitter, and the wavelength tunable laser, the neutral density filter, the beam splitter, the DOE, and the second photodetector are on the same optical axis.

[0011] In an embodiment of the present invention, the first photodetector is used to detect the optical power of the reflected light from the beam splitter, the first digital source meter is used to convert the optical power of the reflected light into a voltage value and output it, the second photodetector is used to detect the optical power of the diffraction light from the DOE, and the second digital source meter is used to convert the optical power of the diffraction light into a voltage value and output it.

[0012] In an embodiment of the present invention, the output end of the first photodetector is connected to the input end of the first digital source meter, and the output end of the second photodetector is connected to the input end of the second digital source meter.

[0013] In an embodiment of the present invention, the LabVIEW software platform includes a processor storing LabVIEW software. The one-dimensional electric displacement stage, the three-dimensional electric displacement stage, the first digital source meter, and the second digital source meter are respectively connected to the processor. The processor is configured to receive the data output by the first digital source meter and the second digital source meter, and is used to run an automatic control program and a data processing program. By running the corresponding automatic control program, the movement of the one-dimensional electric displacement stage and the three-dimensional electric displacement stage is controlled, and by running the data processing program, the optical diffraction efficiency of the DOE is obtained by processing the data from the first digital source meter and the second digital source meter.

[0014] Preferably, the neutral density filter is a gradient neutral density filter or a series of neutral density filters with different OD values.

[0015] In an embodiment of the present invention, the light source wavelength of the laser includes 380 - 1064 nm.

[0016] In an embodiment of the present invention, the OD value of the neutral density filter is OD0.1 - OD4.

[0017] In an embodiment of the present invention, the first photodetector and the second photodetector are respectively photodetectors with adjustable gain, so as to improve the accuracy of the detection results under low brightness detection conditions.

[0018] In an embodiment of the present invention, the one-dimensional displacement stage, the three-dimensional displacement stage, the first digital source meter, and the second digital source meter are respectively connected to the processor through data lines, and the wavelength tunable laser is connected to the processor through Ethernet.

[0019] In an embodiment of the present invention, the sensitivities of the first photodetector and the second photodetector are respectively ≥ 0.1 A / W, and the adjustable gain range is 0 - 70 dB.

[0020] In an embodiment of the present invention, the first digital source meter and the second digital source meter are respectively six-and-a-half-digit digital source meters.

[0021] In an embodiment of the present invention, the measurement errors of the first digital source meter and the second digital source meter are respectively ≤ 0.005%.

[0022] In the second aspect of the present invention, a DOE optical performance testing method based on LabVIEW is further provided, and the DOE optical performance testing system described above is used for DOE optical performance testing.

[0023] Preferably, the DOE optical performance testing method includes the following steps:

[0024] (1) Set up the DOE optical performance testing system;

[0025] (2) Write corresponding automatic control programs and data processing programs in LabVIEW software;

[0026] (3) Turn on the wavelength-tunable laser and set the laser wavelength;

[0027] (4) Set the file storage path, the coordinates of the one-dimensional electric displacement stage, and the coordinates of the three-dimensional electric displacement stage in the LabVIEW software;

[0028] (5) Run the LabVIEW software. Through the corresponding automatic control program, make the one-dimensional electric displacement stage move to the set coordinate position, so that the laser light source passes through the neutral density filter with the required OD value or through the position corresponding to the required OD value on the gradient neutral density filter. Through the corresponding automatic control program, make the three-dimensional electric displacement stage move to the set position, so that the receiving end of the second photodetector is aligned with the diffraction spot to be tested;

[0029] (6) The laser light beam emitted by the wavelength-tunable laser is divided into reflected light (monitoring beam) and transmitted light (detection beam) by the beam splitter after the light power is adjusted by the neutral density filter. The reflected light is detected by the first photodetector, and the light power of the first photodetector is converted into a voltage value by the first digital source meter and then transmitted to the LabVIEW software. The transmitted light is diffracted by the DOE, and the light power of the diffracted light or the diffraction spot is detected by the second photodetector. The light power of the second photodetector is converted into a voltage value by the second digital source meter and transmitted to the LabVIEW software;

[0030] (7) Process the data from the first digital source meter and the second digital source meter through the data processing program to obtain the DOE optical diffraction efficiency;

[0031] (8) Record the light power data from the first digital source meter as the laser power, record the data from the second digital source meter as the DOE power, and record the data processed by the data processing program as the diffraction efficiency, and save them to the target path respectively.

[0032] In some embodiments of the present invention, in the step (4), the coordinates set for the three-dimensional electric displacement stage are the positions where the second photodetector can detect the maximum light intensity value.

[0033] Further, the beam splitting ratio of the beam splitter is 50%, and the calculation method of the optical diffraction efficiency η of the DOE is as follows:

[0034]

[0035] In some other embodiments of the present invention, in step (4), the coordinates of multiple three-dimensional electric displacement stages are set, and the DOE optical performance testing method further includes step (9), and step (9) is as follows: Repeat steps (6) and (7), control the three-dimensional electric displacement stage to move to different coordinates through the automatic control program, respectively obtain the optical diffraction efficiencies η' of different diffraction orders, process through the data processing program to obtain the sum of the optical diffraction efficiencies of different diffraction orders and save it to the target path, which is the optical diffraction efficiency of the DOE.

[0036] Further, the beam splitting ratio of the beam splitter is 50%, and the calculation method of the optical diffraction efficiency η' of different diffraction orders is as follows:

[0037]

[0038] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0039] The DOE optical performance testing system of the present invention can realize the automatic detection of the optical diffraction efficiency of the DOE, reduce the errors caused by the differences in personnel operations, improve the accuracy and testing efficiency of the testing. When the parameter settings in the LabVIEW software are the same, it can ensure that each test is carried out under the same conditions, repeat the same test process, and ensure the comparability of the results, which is crucial for verifying the stability of the product. Description of the Drawings

[0040] Figure 1 It is a schematic structural diagram of the DOE optical performance testing system based on LabVIEW in Embodiment 1;

[0041] Figure 2 It is an automatic testing flow chart of the DOE optical performance testing system based on LabVIEW in this Embodiment 1,

[0042] Among them, Figure 1 in, 11. Wavelength tunable laser; 12. Neutral density filter; 13. One-dimensional electric displacement stage; 14. Beam splitter; 21. First photodetector; 22. First digital source meter; 31. DOE; 32. Three-dimensional electric displacement stage; 33. Second photodetector; 34. Second digital source meter; 4. Processor. Detailed Embodiments

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0044] Embodiment 1

[0045] This embodiment provides a DOE optical performance test system based on LabVIEW, as Figure 1 shown, which includes a laser light source driving module, a light source power detection module, a DOE power detection module, and a LabVIEW software platform.

[0046] Specifically, the laser light source driving module includes a wavelength tunable laser 11, a neutral density filter 12, a one-dimensional electric displacement stage 13, and a beam splitter 14. The neutral density filter 12 is disposed on the one-dimensional electric displacement stage 13 and is located between the wavelength tunable laser 11 and the beam splitter 14. The one-dimensional electric displacement stage 13 is used to adjust the position of the neutral density filter 12 relative to the output end of the wavelength tunable laser 11 to achieve the adjustment of the power of the laser light source.

[0047] Specifically, the light source power detection module includes a first photodetector 21 and a first digital source meter 22. The receiving end of the first photodetector 21 faces the reflecting surface of the beam splitter 14. The first photodetector 21 is used to detect the optical power of the reflected light from the beam splitter 14. The output end of the first photodetector 21 is connected to the input end of the first digital source meter 22. The first digital source meter 22 is used to convert the optical power detected by the first photodetector 21 into a voltage value and output it.

[0048] Specifically, the DOE power detection module includes a DOE 31, a three-dimensional electric displacement stage 32, a second photodetector 33, and a second digital source meter 34. The DOE 31 is located on the side where the transmitting surface of the beam splitter 14 is located. The transmitted light from the beam splitter 14 is the incident light of the DOE 31. The second photodetector 33 is disposed on the three-dimensional electric displacement stage 32. The receiving end of the second photodetector 33 faces the DOE 31. The three-dimensional electric displacement stage 32 is used to adjust the position of the second photodetector 33 to achieve the detection of different diffraction spots. The output end of the second photodetector 33 is connected to the input end of the second digital source meter 34. The second digital source meter 34 is used to convert the optical power detected by the second photodetector 33 into a voltage value and output it.

[0049] Specifically, the LabVIEW software platform includes a processor 4 storing the LabVIEW software. The processor 4 is respectively connected to a one-dimensional electric displacement stage 13, a three-dimensional electric displacement stage 32, a first digital source meter 22, and a second digital source meter 34. The processor 4 is configured to receive the data output by the first digital source meter 22 and the second digital source meter 34, and is used to run corresponding automatic control programs and data processing programs. By running the corresponding automatic control programs, it realizes controlling the movement of the one-dimensional electric displacement stage 13 and the three-dimensional electric displacement stage 32, as well as the wavelength of the laser emitted by the wavelength-tunable laser 11. By running the data processing program, it realizes processing the optical power data from the first digital source meter 22 and the second digital source meter 34 to obtain the optical diffraction efficiency of the DOE 31. When building the test system of this embodiment, the wavelength-tunable laser 11, the neutral density filter 12, the beam splitter 14, the DOE 31, and the second photodetector 33 are on the same optical axis. The connection line between the first photodetector 21 and the beam splitter 14 is perpendicular to the connection line between the second photodetector 33 and the beam splitter 14. The second photodetector 33 is installed at the central position of the three-dimensional electric displacement stage 32.

[0050] In this embodiment, the wavelength-tunable laser 11 can provide stable laser beams with different wavelengths to measure the diffraction efficiency of the DOE 31 at different wavelengths, and the wavelength coverage range is 380 - 1064 nm. The use of the neutral density filter 12 in cooperation with the one-dimensional electric displacement stage 13 can adjust the power of the laser, so that the power of the incident light on the DOE 31 meets the requirements of the DOE 31 and the detection range of the photodetector, thus having a lower power requirement for the laser light source and enabling the measurement of the diffraction efficiency of the DOE 31 under different laser energies. In this embodiment, the laser light source power of the selected wavelength-tunable laser 11 is 100 mW, and the selected neutral density filter 12 is a variable neutral density filter 12 with an OD value of OD0.1 - OD4. In this embodiment, the beam splitting ratio of the beam splitter 14 is 50%. The beam splitter 14 splits the laser beam into a reflected light and a transmitted light with equal energy. The transmitted light serves as the incident light on the DOE 31 and can be called the test beam. By monitoring the optical power of the reflected light in real time, the incident light power on the DOE 31 can be obtained in real time. Therefore, the reflected light can be called the monitoring beam, which reflects the optical power of the incident light on the DOE 31 and avoids the test error caused by the fluctuation of the laser energy.

[0051] In this embodiment, the first photodetector 21 and the second photodetector 33 are respectively photodetectors with adjustable gain, and the sensitivities are respectively ≥ 0.1 A / W, and the adjustable gain range is 0 to 70 dB. The first digital source meter 22 and the second digital source meter 34 are respectively six-and-a-half-digit digital source meters, and the measurement errors are respectively ≤ 0.005%, which are suitable for high-dynamic-range detection from low light intensity to high light intensity. In this embodiment, the one-dimensional electric displacement stage 13, the three-dimensional electric displacement stage 32, the first digital source meter 22 and the second digital source meter 34 are respectively connected to the processor 4 through data lines. In this embodiment, the processor 4 is a computer, and the wavelength-tunable laser 11 is connected to the computer through Ethernet, where the digital source meter is connected to the computer through a GPIB cable and a GPIB card, and the LabVIEW program reads the detected original optical power data in real time.

[0052] The construction of the DOE optical performance test system based on this embodiment and the DOE optical performance test method include the following steps:

[0053] (1) Construct the above DOE optical performance test system;

[0054] (2) Write corresponding automatic control programs and data processing programs in the LabVIEW software;

[0055] (3) Turn on the wavelength-tunable laser 11 and set the laser wavelength in the software supporting the wavelength-tunable laser 11;

[0056] (4) Set the file storage path, the coordinates of the one-dimensional electric displacement stage 13, and the coordinates of the three-dimensional electric displacement stage 32 in the LabVIEW software;

[0057] (5) Run the LabVIEW software, and move the one-dimensional electric displacement stage 13 to the set coordinate position through the corresponding automatic control program, so that the laser light source passes through the position corresponding to the required OD value on the neutral density filter or the gradient neutral density filter with the required OD value;

[0058] (6) Move the three-dimensional electric displacement stage 32 to the set position through the corresponding automatic control program, so that the second photodetector 33 is aligned with the diffraction spot to be tested. After the optical power is adjusted by the neutral density filter, the light beam is split into a monitoring beam (reflected light) and a detection beam (transmitted light) by the beam splitter 14. The optical power of the monitoring beam is detected by the first photodetector 21, and the optical power of the first photodetector 21 is converted into a voltage value by the first digital source meter 22 and then transmitted to the LabVIEW software; the detection beam is diffracted by the DOE 31, the optical power of the diffracted light or the diffraction spot is detected by the second photodetector 33, and the optical power of the second photodetector 33 is converted into a voltage value by the second digital source meter 34 and transmitted to the LabVIEW software;

[0059] (7) The diffraction efficiency η of the DOE 31 is obtained by processing the voltage values from the first digital source table 22 and the second digital source table 34 through a data processing program:

[0060]

[0061] (8) The original data of the voltage values from the first digital source table 22 is recorded as the laser power, the original data of the voltage values from the second digital source table 34 is recorded as the DOE 31 power, and the data processed by the data processing program is recorded as the diffraction efficiency, which are respectively saved to the target path.

[0062] If it is necessary to test the diffraction efficiencies of multiple different diffraction spots, only the coordinate set of the three-dimensional motorized displacement stage 32 needs to be input in step (4) or the moving direction and moving distance of the three-dimensional motorized displacement stage 32 need to be set, and then steps (5) and (6) are repeated. After the test of the previous diffraction point is completed, the three-dimensional motorized displacement stage 32 is automatically controlled by the LabVIEW software to move to the next coordinate to complete the corresponding test, and data processing is performed, so as to obtain the optical diffraction efficiencies of different diffraction orders of the DOE 31 and the sum of the optical diffraction efficiencies of different diffraction orders, which is the optical diffraction efficiency of the DOE 31. The calculation method of the optical diffraction efficiency η' of different diffraction orders is as follows:

[0063]

[0064] The original data of the voltage values (laser power and DOE power) and the data processing results (diffraction efficiency) are both displayed on the human-machine interaction interface.

[0065] Embodiment 2

[0066] This embodiment provides a method for testing the single-point diffraction efficiency at a known position of a DOE by using the DOE optical performance testing system of Embodiment 1. The steps are as follows:

[0067] (1) Set up the DOE optical performance testing system according to Embodiment 1;

[0068] (2) Write the corresponding automatic control program and data processing program in the LabVIEW software;

[0069] (3) Turn on the wavelength-tunable laser 11 and set the laser wavelength to 940 nm;

[0070] (4) In the control panel of the human-machine interaction interface of the upper computer LabVIEW software platform, set the file storage path, select the test mode as single-point test, and set the coordinates of the one-dimensional electric displacement stage 13 and the coordinates of the three-dimensional electric displacement stage 32. The coordinates of the one-dimensional electric displacement stage 13 are set as follows: taking the leftmost movement starting point of the one-dimensional electric displacement stage 13 as the origin x = 0, determine the accurate moving distance that can adjust the optical power of the light source to within the DOE test requirement range by manual or other means, input this moving distance. In this embodiment, the one-dimensional electric displacement stage moves to the corresponding coordinate x = 5 mm for OD0.5; the coordinates of the three-dimensional electric displacement stage 32 are set as follows: taking the initialization position of the three-dimensional electric displacement stage 32 as the origin (0, 0, 0), pre-find the position of the maximum light intensity by moving the three-dimensional displacement stage. At this time, the probe of the second photodetector 33 is aligned with the diffraction spot of the DOE 31, and confirm the coordinates x, y, z; the accurate coordinates input in this embodiment are (2 mm, 3 mm, 5 mm);

[0071] (5) Run the automatic control program in the upper computer LabVIEW software platform. The LabVIEW program sends instructions to the one-dimensional electric displacement stage 13 through the network cable. After receiving the instructions, the one-dimensional electric displacement stage 13 moves to the set position;

[0072] (6) The LabVIEW program sends instructions to the three-dimensional electric displacement stage 32 through the network cable. After receiving the instructions, the three-dimensional electric displacement stage 32 moves to the accurate coordinates (2 mm, 3 mm, 5 mm);

[0073] (7) The LabVIEW program reads the voltage value of the first digital source meter 22 and the voltage value of the second digital source meter 34 through GPIB, and processes the voltage values from the first digital source meter 22 and the second digital source meter 34 to obtain the optical diffraction efficiency η of the DOE 31:

[0074]

[0075] (8) Record the original data of the voltage value from the first digital source meter 22 as the laser power, record the original data of the voltage value from the second digital source meter 34 as the DOE power, and record the data processed by the data processing program as the diffraction efficiency, and save them to the target path and display them on the human-machine interaction interface.

[0076] The test results of this embodiment are shown in Table 1.

[0077] Table 1

[0078]

[0079] Example 3

[0080] This embodiment provides a method for testing the diffraction efficiency of multiple points with a fixed pitch at known positions of a DOE using the DOE optical performance testing system of Embodiment 1. The steps for the system to run by itself are as follows:

[0081] (1) Set up the DOE optical performance testing system according to Embodiment 1;

[0082] (2) Write corresponding automatic control programs and data processing programs in the LabVIEW software;

[0083] (3) Turn on the wavelength-tunable laser 11 and set the laser wavelength to 940 nm;

[0084] (4) In the control panel of the human-computer interaction interface of the upper computer LabVIEW software platform, set the file storage path, select the test mode as fixed pitch test, and set the coordinates of the one-dimensional electric displacement stage 13 and the coordinates of the three-dimensional electric displacement stage 32. Among them, the coordinate setting of the one-dimensional electric displacement stage 13 is the same as that in Embodiment 1. The coordinate position of the three-dimensional electric displacement stage 32 is the position where the probe of the second photodetector 33 is aligned with one point in the diffraction array points of the DOE 31 as the coordinate origin. Set the test range and test pitch of the three-dimensional electric displacement stage 32 in the x, y, and z directions. In this embodiment, set the test pitch in the x-axis to 10 mm, the x-axis range to 40 mm, and the y-axis and z-axis ranges to 0;

[0085] (5) Run the automatic control program in the upper computer LabVIEW software platform. The LabVIEW program sends instructions to the one-dimensional electric displacement stage 13 through the network cable. After receiving the instructions, the one-dimensional electric displacement stage 13 moves to the set position;

[0086] (6) The LabVIEW program calculates the coordinate combinations of x, y, and z in the background according to the set test range and test pitch of the three-dimensional electric displacement stage 32 in the x, y, and z directions. After the LabVIEW program reads the first coordinate position, it sends instructions to the three-dimensional electric displacement stage 32 through the network cable. After receiving the instructions, the three-dimensional electric displacement stage 32 moves to the set coordinates of x, y, and z;

[0087] (7) The LabVIEW program reads the voltage values of the first digital source meter 22 and the second digital source meter 34 through GPIB, and processes the voltage values from the first digital source meter 22 and the second digital source meter 34 through the data processing program to obtain the optical diffraction efficiency η' of one of the diffraction orders of the DOE 31:

[0088]

[0089] (8) Record the original voltage value data from the first digital source table 22 as the laser power, record the original voltage value data from the second digital source table 34 as the DOE power, and record the data processed by the data processing program as the diffraction efficiency, and save them to the target path respectively;

[0090] (9) After completing one test, the LabVIEW program continues to read the next coordinate position of the three-dimensional electric displacement stage 32, sends instructions to the three-dimensional electric displacement stage 32 through the network cable, and the three-dimensional electric displacement stage 32 can automatically move to the next position for testing. This cycle continues until the entire test is completed, obtaining the optical diffraction efficiency of different diffraction orders. Through data processing, the sum (η) of the optical diffraction efficiencies of different diffraction orders is obtained. The LabVIEW program automatically stores the data in tabular form and saves it in the target path, completing the automated test of the optical diffraction efficiency of the DOE 31. The test results of this embodiment are shown in Table 2.

[0091] Table 2

[0092]

[0093] Example 4

[0094] This embodiment provides a method for testing the multi-point diffraction efficiency at known positions of a DOE using the DOE optical performance test system of Example 1. The steps for the system to run by itself are as follows:

[0095] (1) Set up the DOE optical performance test system according to Example 1;

[0096] (2) Write the corresponding automatic control program and data processing program in the LabVIEW software;

[0097] (3) Turn on the wavelength-tunable laser 11 and set the laser wavelength to 940 nm;

[0098] (4) In the control panel of the human-computer interaction interface of the upper computer LabVIEW software platform, set the file storage path, select the test mode as fixed-spacing test, and set the coordinates of the one-dimensional electric displacement stage 13 and the three-dimensional electric displacement stage 32. The coordinates of the one-dimensional electric displacement stage 13 are set the same as in Example 1. Set the test mode as user-defined. The user can pre-create an excel table. Using the initial position of the three-dimensional electric displacement stage 32 as the origin, input the coordinate combinations of x, y, and z for each diffraction point. The coordinate combinations set in this embodiment are shown in Table 3. Then input this excel file into the LabVIEW program;

[0099] (5) Run the automatic control program in the upper computer LabVIEW software platform. The LabVIEW program sends instructions to the one-dimensional electric displacement stage 13 via the network cable. After receiving the instructions, the one-dimensional electric displacement stage 13 moves to the set position;

[0100] (6) The LabVIEW program reads the coordinate combinations of x, y, and z in the excel file. After reading the first coordinate position, it sends instructions to the three-dimensional electric displacement stage 32 via the network cable. After receiving the instructions, the three-dimensional electric displacement stage 32 moves to the set position;

[0101] (7) The LabVIEW program reads the voltage values of the first digital source meter 22 and the second digital source meter 34 through GPIB, and processes the voltage values from the first digital source meter 22 and the second digital source meter 34 through a data processing program to obtain the optical diffraction efficiency η' of one of the diffraction orders of the DOE 31:

[0102]

[0103] (8) Record the original data of the voltage value from the first digital source meter 22 as the laser power, record the original data of the voltage value from the second digital source meter 34 as the DOE power, and record the data processed by the data processing program as the diffraction efficiency η', and save them to the target path respectively;

[0104] (9) After completing one test, the LabVIEW program continues to read the next coordinate position of the three-dimensional electric displacement stage 32, sends instructions to the three-dimensional electric displacement stage 32 via the network cable, and the three-dimensional electric displacement stage 32 can automatically move to the next position for testing. This cycle continues until the entire test is completed to obtain the optical diffraction efficiencies of different diffraction orders. The sum (η) of the optical diffraction efficiencies of different diffraction orders is obtained through data processing. The LabVIEW program automatically stores the data in tabular form and saves it in the target path, completing the automated test of the diffraction efficiency of the DOE 31. The test results of this embodiment are shown in Table 3.

[0105] Table 3

[0106]

[0107] In Examples 2 to 4, single-point and multi-point diffraction are used to detect the optical diffraction efficiency of the same DOE, and the detection results have good consistency. The multi-point diffraction detection results of Example 3 and Example 4 only differ by 0.05%.

[0108] The above embodiments achieve the automated detection of the optical diffraction efficiency of the DOE, improve the accuracy and test efficiency of the test, and ensure the comparability of the results.

[0109] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It is not intended to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A DOE optical performance test system based on LabVIEW, characterized in that: It includes: A laser light source driving module, comprising a wavelength tunable laser, a neutral density filter, a one-dimensional electric translation stage and a beam splitter, wherein the neutral density filter and the one-dimensional electric translation stage are located between the wavelength tunable laser and the beam splitter, and the neutral density filter is arranged on the one-dimensional electric translation stage; A light source power detection module, comprising a first photodetector and a first digital source meter, wherein a receiving end of the first photodetector faces a reflecting surface of the beam splitter, and the first digital source meter is connected to the first photodetector; A DOE power detection module, comprising a DOE, a three-dimensional electric translation stage, a second photodetector and a second digital source meter, wherein the DOE is located on the side where the transmission surface of the beam splitter is located, the second photodetector is arranged on the three-dimensional electric translation stage, the receiving end of the second photodetector faces the DOE, and the second digital source meter is connected to the second photodetector; A LabVIEW software platform is used to control the movement of the one-dimensional electric translation stage and the three-dimensional electric translation stage, and to process data from the first digital source meter and the second digital source meter to obtain the optical diffraction efficiency of the DOE.

2. The DOE optical performance test system according to claim 1, characterized in that: The line connecting the first photodetector and the beam splitter is perpendicular to the line connecting the second photodetector and the beam splitter, the wavelength tunable laser, the neutral density filter, the beam splitter, the DOE and the second photodetector are on the same optical axis, The first photodetector is used to detect the optical power of the reflected light from the beam splitter, and the first digital source meter is used to convert the optical power of the reflected light into a voltage value output. The second photodetector is used to detect the optical power of the diffracted light from the DOE, and the second digital source meter is used to convert the optical power of the diffracted light into a voltage value output.

3. The DOE optical performance test system according to claim 1, characterized in that: The output end of the first photodetector is connected to the input end of the first digital source meter, and the output end of the second photodetector is connected to the input end of the second digital source meter. The LabVIEW software platform includes a processor storing LabVIEW software. The one-dimensional electric translation stage, the three-dimensional electric translation stage, the first digital source meter and the second digital source meter are respectively connected to the processor. The processor is configured to receive data output by the first digital source meter and the second digital source meter, and is used to run an automatic control program and a data processing program. The movement of the one-dimensional electric translation stage and the three-dimensional electric translation stage is controlled by running the corresponding automatic control program, and the data from the first digital source meter and the second digital source meter are processed by running the data processing program to obtain the optical diffraction efficiency of the DOE.

4. The DOE optical performance test system according to claim 1, characterized in that: The wavelength of the laser light source is 380-1064nm; And / or, the neutral density filter is a gradient neutral density filter or a series of neutral density filters with different OD values; And / or, the OD value of the neutral density filter is OD0.1-OD4.

5. The DOE optical performance test system according to claim 3, characterized in that: The one-dimensional translation stage, the three-dimensional translation stage, the first digital source meter and the second digital source meter are respectively connected to the processor via data lines, and the wavelength tunable laser is connected to the processor via Ethernet.

6. The DOE optical performance test system according to claim 1, characterized in that: The first photodetector and the second photodetector are gain-adjustable photodetectors, respectively. The sensitivity of the first photodetector and the second photodetector is ≥ 0.1A / W, respectively, and the gain adjustable range is 0 to 70dB; and / or, the first digital source meter and the second digital source meter are six-and-a-half-digit digital source meters respectively; And / or, the measurement errors of the first digital source meter and the second digital source meter are respectively ≤0.005%.

7. A DOE optical performance testing method based on LabVIEW, characterized in that: The DOE optical performance test system according to any one of claims 1 to 6 is used to perform DOE optical performance test.

8. The DOE optical performance testing method according to claim 7, characterized in that: The DOE optical performance testing method comprises the following steps: (1) Building the DOE optical performance test system; (2) Write the corresponding automatic control program and data processing program in LabVIEW software; (3) Turn on the wavelength tunable laser and set the laser wavelength; (4) Set the file storage path, the coordinates of the one-dimensional electric translation stage, and the coordinates of the three-dimensional electric translation stage in the LabVIEW software; (5) running LabVIEW software and moving the one-dimensional electric translation stage to the set coordinate position through the corresponding automatic control program, so that the laser light source passes through the neutral density filter of the required OD value or passes through the position on the gradient neutral density filter corresponding to the required OD value; (6) The three-dimensional electric translation stage is moved to the set position through the corresponding automatic control program, so that the receiving end of the second photodetector is aligned with the diffraction light or diffraction spot to be tested. The laser light source light beam emitted by the wavelength tunable laser is adjusted for optical power through a neutral density filter and then divided into reflected light and transmitted light through a beam splitter. The reflected light is detected by the first photodetector, and the optical power of the first photodetector is converted into a voltage value through a first digital source meter and then transmitted to the LabVIEW software. The transmitted light is diffracted by the DOE, and the optical power of the diffraction light or diffraction spot is detected by the second photodetector. The optical power of the second photodetector is converted into a voltage value through a second digital source meter and then transmitted to the LabVIEW software. (7) Processing the voltage values ​​from the first digital source meter and the second digital source meter by a data processing program to obtain the DOE optical diffraction efficiency; (8) The original data from the first digital source meter and the second digital source meter and the data processed by the data processing program are saved to the target path respectively.

9. The DOE optical performance testing method according to claim 8, characterized in that: In the step (4), the coordinates of the three-dimensional electric translation stage are set to a position at which the second photodetector can detect a maximum light intensity value.

10. The DOE optical performance testing method according to claim 8, characterized in that: The beam splitting ratio of the beam splitter is 50%, and the calculation method of the optical diffraction efficiency η of the DOE is:

11. The DOE optical performance testing method according to claim 8, characterized in that: In the step (4), the coordinates of the multiple three-dimensional electric translation stages are set. The DOE optical performance testing method also includes a step (9), which is: repeating steps (6) and (7), controlling the three-dimensional electric translation stage to move to different coordinates through the automatic control program, and obtaining the optical diffraction efficiency η' of different diffraction orders respectively, and obtaining the sum of the optical diffraction efficiencies of the different diffraction orders through the data processing program and saving it to the target path, which is the optical diffraction efficiency of the DOE.

12. The DOE optical performance testing method according to claim 11, characterized in that: The beam splitting ratio of the beam splitter is 50%, and the calculation method of the optical diffraction efficiency η' of different diffraction orders is:

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