Automatic measurement system for SLM liquid crystal light response curve

Abstract

The utility model provides an automatic measuring system for an SLM liquid crystal light response curve, which relates to the technical field of liquid crystal light response curve measurement and comprises a laser, an SLM liquid crystal spatial light modulator, an upper computer, a diffraction energy level light spot adjusting mechanism and a power meter. The laser is used for emitting light; the diffraction energy level light spot adjusting mechanisms are arranged between the laser and the SLM liquid crystal spatial light modulator and between the SLM liquid crystal spatial light modulator and the power meter and used for obtaining + 1 level diffraction light spots. The SLM liquid crystal spatial light modulator is used for loading different phase diagrams; the power meter is used for receiving + 1-level diffraction spots and collecting power; and the upper computer is in control connection with the power meter and the SLM liquid crystal spatial light modulator. According to the automatic measuring system provided by the utility model, data can be obtained only by manually starting an automatic process, so that the time of experimenters is greatly saved.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid crystal light response curve measurement, in particular to an automatic measurement system for a SLM liquid crystal light response curve. Background Art

[0002] SLM is a liquid crystal spatial light modulator, which is a device that uses the principle that when light passes through liquid crystal under different voltages, the phase changes accordingly to achieve phase modulation of the incident laser. On the liquid crystal working surface of SLM, each pixel represents a tiny block of liquid crystal, and different phase diagrams are loaded onto the liquid crystal surface. The grayscale value of the phase diagram represents the different voltages loaded onto the liquid crystal. The ability of liquid crystal to adjust the phase of the light passing through varies according to the wavelength of the incident light; for incident light of the same wavelength band, the phase change amount is a nonlinear curve as the voltage changes. Therefore, in order to accurately modulate the phase of the light source, it is necessary to measure the light response curve of the liquid crystal applied voltage of light sources of different wavelengths.

[0003] Current systems for measuring the response curve of liquid crystals: Figure 1 The optical path is then loaded onto the SLM liquid crystal surface one by one through the SLM software. The phase-modulated light in the direction of the outgoing light will diffract and form a diffraction energy level spot. After being focused by the lens, the optical power of the first-order diffraction spot is obtained through the detector on the focal plane of the lens. The first-order spot power of all phase diagrams is measured and recorded to form a response curve.

[0004] The main problems with current systems for measuring the photoresponse curve of liquid crystals are:

[0005] First, in the above measurement system, the outgoing light is focused by the lens, and the spatial position of the diffraction energy level spot is distinguished on the focal plane, and the detector receives the first-order diffraction spot. However, the spatial distance between two adjacent spots is often relatively small, and the target surface of the detector will detect the power of adjacent spots at the same time, causing errors.

[0006] Secondly, during the measurement, the detector generally directly displays the detection reading on the detection device screen, and the reading is read manually. Therefore, the phase diagram switching in the SLM device software needs to adapt to the manual speed, and the next phase diagram should be switched after the data is recorded. If the optical path is not successfully built, the laser power is unstable, or other hardware and software problems occur, the manually recorded data will be invalidated, and after adjusting the optical path, it needs to be manually recorded again. Repeatedly measuring the same set of data consumes time and energy.

[0007] Third, due to the second point, the phase diagram loading speed of the SLM device must adapt to the manual speed, and it is impossible to load the phase diagram automatically, which leads to an increase in workload.

[0008] Therefore, there is room for improvement. The utility model provides an automatic measurement system for an SLM liquid crystal light response curve. Utility Model Content

[0009] In view of the shortcomings of the prior art, the utility model aims to provide an automatic measurement system for the light response curve of SLM liquid crystal. The specific scheme is as follows:

[0010] An automatic measurement system for an SLM liquid crystal light response curve, the automatic measurement system comprising a laser, an SLM liquid crystal spatial light modulator, a host computer, a diffraction energy level spot adjustment mechanism, and a power meter;

[0011] Laser is used to emit light source;

[0012] The diffraction energy level spot adjustment mechanism is arranged between the laser and the SLM liquid crystal spatial light modulator and between the SLM liquid crystal spatial light modulator and the power meter, and is used to obtain the +1 order diffraction spot;

[0013] The SLM liquid crystal spatial light modulator is used to load different phase images;

[0014] The power meter is used to receive the +1-order diffraction spot and collect power;

[0015] The host computer is connected to the power meter and the SLM liquid crystal spatial light modulator control.

[0016] Furthermore, the diffraction energy level spot adjustment mechanism includes a polarizer, a lens, a reflector, and an aperture;

[0017] The laser, polarizer, and SLM liquid crystal spatial light modulator are arranged in sequence along the incident direction A of the light source in the laser, the reflector, aperture, and power meter are arranged in sequence along the light reflection direction B of the reflector, and the SLM liquid crystal spatial light modulator, lens, and reflector are arranged in sequence along the light emission direction C of the SLM liquid crystal spatial light modulator;

[0018] Furthermore, an angle is set between the incident direction A and the light emitting direction C.

[0019] Furthermore, the angle between the incident direction A and the light emitting direction C does not exceed 7°.

[0020] Furthermore, the diffraction energy level spot adjustment mechanism includes a polarizer, a beam splitter, a lens, a reflector, and an aperture;

[0021] The laser, polarizer, beam splitter, and SLM liquid crystal spatial light modulator are arranged in sequence along the incident direction A of the light source in the laser, and the reflector, lens, aperture, and power meter are arranged in sequence along the light reflection direction B of the reflector;

[0022] The angle between the incident light and the reflected light of the dichroic prism is 0°, and the mirror surfaces of the dichroic prism and the reflector are arranged in parallel.

[0023] Furthermore, the laser can be replaced with different laser bands.

[0024] Furthermore, the polarization direction of the laser light passing through the polarizer is consistent with the direction required by the liquid crystal modulation phase of the SLM liquid crystal spatial light modulator.

[0025] Furthermore, there are at least 256 phase images in the SLM liquid crystal spatial light modulator.

[0026] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0027] (1) Laser, SLM liquid crystal spatial light modulator, diffraction energy level spot adjustment mechanism, etc. are used as hardware optical path design. The utility model forms an automatic measurement system for automatic processing through hardware optical path design and upper computer software control. Specifically, the automatic process processes phase map generation, SLM phase map loading switching, and power meter measurement result recording and data generation.

[0028] After the system is built, the laser emits a light source, and through the cooperation of the SLM liquid crystal spatial light modulator and the diffraction energy level spot adjustment mechanism, the laser spot modulated by the SLM liquid crystal spatial light modulator appears a diffraction energy level spot, and the power meter receives the +1 diffraction energy level spot. As long as the laser band of the laser is changed, the data can be automatically recorded to generate the response curve of the SLM liquid crystal of the corresponding band.

[0029] (2) With the automatic measurement system of the present invention, humans only need to start the automated process to obtain data, which greatly saves the time of the experimenters. In addition, the personnel can leave the test environment, which can ensure the environmental stability when testing the SLM liquid crystal, that is, there is no ambient light and no air disturbance caused by human activities. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 An optical path diagram of a system for measuring a response curve of a liquid crystal in the background art;

[0031] Figure 2 The optical path of the automatic measurement system in the utility model Figure 1 ;

[0032] Figure 3 The effect diagram showing the diffraction energy level spot on the focal plane of the lens;

[0033] Figure 4 The optical path of the automatic measurement system in the utility model Figure 2 .

[0034] Figure numerals: 1. laser; 2. SLM liquid crystal spatial light modulator; 3. host computer; 4. power meter; 5. polarizer; 6. lens; 7. reflector; 8. aperture; 9. dichroic prism. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below in conjunction with the embodiments and drawings, but the implementation methods of the present invention are not limited thereto.

[0036] In order to realize the automatic processing of switching SLM phase diagram, the detector measures the automatic measurement data of the diffraction spot formed by the corresponding phase diagram, the utility model proposes an automatic measurement system for the SLM liquid crystal light response curve, which is composed of automation software and hardware optical path, and can complete the test process.

[0037] Specifically, the automatic measurement system includes a laser 1, an SLM liquid crystal spatial light modulator 2, and a host computer 3. These three components can adopt existing structures without specific restrictions. In addition to these existing structures, it also includes a diffraction energy level spot adjustment mechanism and a power meter 4.

[0038] The host computer 3 is provided with automation software, and the SLM liquid crystal spatial light modulator 2 and the power meter 4 are controlled by the automation software in the host computer 3. The laser 1 and the diffraction energy level spot adjustment mechanism serve as the hardware optical path.

[0039] Among them, the laser 1 is used for emitting light source, and the laser 1 can be replaced with different laser bands;

[0040] The diffraction energy level spot adjustment mechanism is arranged between the laser 1 and the SLM liquid crystal spatial light modulator 2 and between the SLM liquid crystal spatial light modulator 2 and the power meter 4. By adopting different diffraction energy level spot adjustment mechanisms, it can be used to obtain the +1 order diffraction spot;

[0041] The SLM liquid crystal spatial light modulator 2 is used to load different phase maps, and the phase maps in the SLM liquid crystal spatial light modulator 2 are at least 256;

[0042] The power meter 4 is used to receive the +1-order diffraction spot and collect power;

[0043] The host computer 3 is connected to the power meter 4 and the SLM liquid crystal spatial light modulator 2 for control.

[0044] like Figure 2First, the diffraction energy level spot adjustment mechanism includes a polarizer 5, a lens 6, a reflector 7, and an aperture 8. The laser 1, the polarizer 5, and the SLM liquid crystal spatial light modulator 2 are arranged in sequence along the incident direction A of the light source in the laser 1. The reflector 7, the aperture 8, and the power meter 4 are arranged in sequence along the light reflection direction B of the reflector 7. The SLM liquid crystal spatial light modulator 2, the lens 6, and the reflector 7 are arranged in sequence along the light emitting direction C of the SLM liquid crystal spatial light modulator 2.

[0045] As can be seen from the figure, the incident direction A and the light reflection direction B can be set horizontally, while the light emitting direction C is set obliquely, and an angle is set between the incident direction A and the light emitting direction C.

[0046] It should be noted that the angle between the incident direction A and the light emitting direction C does not exceed 7°, and may be less than or equal to 7°, so as to reduce interference between liquid crystal pixels.

[0047] It should be noted that the polarization direction of the laser light passing through the polarizer 5 is consistent with the direction required by the liquid crystal modulation phase of the SLM liquid crystal spatial light modulator 2 .

[0048] When the laser 1 emits a light source, it passes through the polarizer 5 to form polarized light in a specific direction. The laser is incident on the SLM liquid crystal spatial light modulator 2, and the outgoing light is modulated by the SLM liquid crystal spatial light modulator 2 to obtain an outgoing laser with a specific phase. When the SLM liquid crystal spatial light modulator 2 is loaded with a grating (chessboard) phase diagram, the laser spot modulated by the SLM liquid crystal spatial light modulator 2 will have a diffraction energy level spot, and the diffraction energy level spot power changes according to the phase distribution of the outgoing laser. The outgoing laser is focused by the telephoto lens 6 and the plane reflector 7 changes the direction of the optical path. On the focal plane of the lens 6, the 0th order, +1st order, and -1st order diffraction spots are focused as light spots, respectively, as shown in FIG. Figure 3 shown. Figure 3 In the figure, the middle light spot is the 0th order diffraction spot, and the left and right sides are the +1st order diffraction spot and -1st order diffraction spot respectively.

[0049] The aperture 8 is at the focal plane of the lens 6, filtering the 0th order diffraction spot and the -1st order diffraction spot, and the +1st order diffraction spot passes through the aperture 8 and is received by the power meter 4. The laser 1, the SLM liquid crystal spatial light modulator 2 and the power meter 4 are controlled by a program on the host computer 3: the SLM liquid crystal spatial light modulator 2 is controlled to load different phase diagrams, and the power meter 4 automatically collects the power of the +1st order diffraction spot of the diffraction energy level of the outgoing light of the SLM liquid crystal spatial light modulator 2 when different phase diagrams are present.

[0050] The entire automatic measurement system is controlled by the host computer 3. The program automatically loads and switches the phase map on the SLM. The power meter 4 automatically measures the power of the +1 order diffraction spot after each phase map is loaded. The data of 256 phase maps are recorded and processed into a readable data format.csv.

[0051] After the hardware system is built, just by changing the laser band of laser 1, the data can be automatically recorded and the response curve of the SLM liquid crystal can be generated.

[0052] like Figure 4 Secondly, the diffraction energy level spot adjustment mechanism may also include a polarizer 5, a beam splitter prism 9, a lens 6, a reflector 7, and an aperture 8. The laser 1, the polarizer 5, the beam splitter prism 9, and the SLM liquid crystal spatial light modulator 2 are arranged in sequence along the incident direction A of the light source in the laser 1, and the reflector 7, the lens 6, the aperture 8, and the power meter 4 are arranged in sequence along the light reflection direction B of the reflector 7.

[0053] It should be noted that the angle between the incident light and the reflected light of the beam splitter prism 9 is 0° to avoid interference between liquid crystal pixels, and the mirror surfaces of the beam splitter prism 9 and the reflector 7 are arranged in parallel to facilitate the reflector 7 to receive the light from the beam splitter prism 9.

[0054] It should be noted that the polarization direction of the laser light passing through the polarizer 5 is consistent with the direction required by the liquid crystal modulation phase of the SLM liquid crystal spatial light modulator 2 .

[0055] The light source is generated by laser 1, and a linearly polarized laser with a determined polarization direction is obtained through polarizer 5. BS is a beam splitter prism 9. After passing through BS, the laser enters SLM liquid crystal spatial light modulator 2, and returns to beam splitter prism 9 coaxially after reflection. The laser reflected by SLM is modulated laser. When SLM liquid crystal spatial light modulator 2 is loaded with a grating phase diagram, the modulated laser will have a diffraction energy level. The modulated laser reflected by beam splitter prism 9 is incident on reflector 7, and after being reflected, it is focused by lens 6. The modulated laser after focusing converges into a diffraction light spot at the focal plane of lens 6, as shown in FIG. Figure 3 As shown, only the +1-order diffraction light spot passes through the aperture 8, and the other light spots are filtered by the aperture 8. The power meter 4 receives the +1-order diffraction light spot and measures the light spot power.

[0056] Similarly, the entire automatic measurement system is controlled by the host computer 3, which automatically loads and switches the phase map on the SLM through the program, and the power meter 4 automatically measures the power of the +1 order diffraction spot after each phase map is loaded. The data of 256 phase maps are recorded and processed into a readable data format.csv.

[0057] The above is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. An automatic measurement system for a SLM liquid crystal light response curve, the automatic measurement system comprising a laser (1), a SLM liquid crystal spatial light modulator (2), and a host computer (3), characterized in that: It also includes a diffraction energy level spot adjustment mechanism and a power meter (4); The laser (1) is used to emit a light source; The diffraction energy level spot adjustment mechanism is arranged between the laser (1) and the SLM liquid crystal spatial light modulator (2) and between the SLM liquid crystal spatial light modulator (2) and the power meter (4), and is used to obtain a +1 order diffraction spot; The SLM liquid crystal spatial light modulator (2) is used to load different phase images; The power meter (4) is used to receive the +1-order diffraction spot and collect power; The host computer (3) is connected to the power meter (4) and the SLM liquid crystal spatial light modulator (2) for control.

2. The automatic measurement system for the SLM liquid crystal light response curve according to claim 1, characterized in that: The diffraction energy level spot adjustment mechanism comprises a polarizing plate (5), a lens (6), a reflecting mirror (7), and a diaphragm (8); The laser (1), the polarizing plate (5), and the SLM liquid crystal spatial light modulator (2) are arranged in sequence along an incident direction A of a light source in the laser (1); the reflector (7), the aperture (8), and the power meter (4) are arranged in sequence along a light reflection direction B of the reflector (7); and the SLM liquid crystal spatial light modulator (2), the lens (6), and the reflector (7) are arranged in sequence along a light emission direction C of the SLM liquid crystal spatial light modulator (2); Furthermore, an angle is set between the incident direction A and the light emitting direction C.

3. The automatic measurement system for the SLM liquid crystal light response curve according to claim 2, characterized in that: And the angle between the incident direction A and the light emitting direction C does not exceed 7°.

4. The automatic measurement system for the SLM liquid crystal light response curve according to claim 1, characterized in that: The diffraction energy level spot adjustment mechanism comprises a polarizing plate (5), a beam splitter prism (9), a lens (6), a reflector (7), and an aperture (8); The laser (1), polarizing plate (5), beam splitter prism (9), and SLM liquid crystal spatial light modulator (2) are arranged in sequence along the incident direction A of the light source in the laser (1); and the reflector (7), lens (6), aperture (8), and power meter (4) are arranged in sequence along the light reflection direction B of the reflector (7); The angle between the incident light and the reflected light of the beam splitter prism (9) is 0°, and the mirror surfaces of the beam splitter prism (9) and the reflector (7) are arranged in parallel.

5. The automatic measurement system for the SLM liquid crystal light response curve according to claim 1, characterized in that: The laser (1) can be replaced with different laser bands.

6. The automatic measurement system for SLM liquid crystal light response curve according to claim 2 or 4, characterized in that: The polarization direction of the laser light passing through the polarizing plate (5) is consistent with the direction required by the liquid crystal modulation phase of the SLM liquid crystal spatial light modulator (2).

7. The automatic measurement system for the SLM liquid crystal light response curve according to claim 1, characterized in that: The SLM liquid crystal spatial light modulator (2) has at least 256 phase images.

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