A laser three-dimensional imaging simulator

Abstract

The present invention relates to a laser three-dimensional imaging simulator, which belongs to the field of three-dimensional imaging simulators and is used to solve the defect that the existing technology cannot flexibly adjust the simulation distance. The laser three-dimensional imaging simulator includes a laser, a fiber array coupler, a fiber array composed of fiber bundles with increasing lengths, a liquid crystal spatial light modulator, a spatial filtering optical system, a pinhole diaphragm arranged on the focal plane of the spatial filtering optical system, and a test system, wherein the light beam emitted by the laser is collimated and projected to the fiber array coupler, and then decomposed and enters the fiber array; the output light of the fiber array is collimated and projected to the liquid crystal spatial light modulator; among the light beams output by the liquid crystal spatial light modulator, the light beam passing through the pinhole diaphragm is collimated and projected to the test system. One application of the present invention is the design and manufacture of a laser three-dimensional imaging simulator.

Description

Technical Field

[0001] The invention relates to the field of three-dimensional imaging simulators, and in particular to a laser three-dimensional imaging simulator. Background Art

[0002] Prior art such as CN1085357388 discloses a three-dimensional close-range imaging simulator, which uses optical fiber discs of different lengths to simulate optical signal delays at different distances. However, the aforementioned document cannot flexibly adjust the simulation distance, but sets fixed lengths of 41m, 55m, 69m, 83m, and 89m optical fibers. If you want to change the simulation distance, you need to remodel the device and readjust the optical fiber length, making the device unsuitable for a wide range of application scenarios. Summary of the invention

[0003] An object of the present invention is to solve the defect that the prior art cannot flexibly adjust the simulation distance.

[0004] According to a first aspect of the present invention, there is provided a laser three-dimensional imaging simulator, comprising a laser, a fiber array coupler, a fiber array consisting of fiber bundles of increasing lengths, a liquid crystal spatial light modulator, a spatial filtering optical system, a pinhole aperture arranged on the focal plane of the spatial filtering optical system, and a test system, wherein a light beam emitted by the laser is collimated and projected to the fiber array coupler, and then decomposed and enters the fiber array; the output light of the fiber array is collimated and projected to the liquid crystal spatial light modulator; and among the light beams output by the liquid crystal spatial light modulator, the light beam that passes through the pinhole aperture is collimated and projected to the test system.

[0005] Preferably, the liquid crystal spatial light modulator is configured to perform spatial two-dimensional angle deflection of an incident light beam through a phase delay function of a liquid crystal subunit, so as to achieve output of a light beam having a specified incident angle being deflected to an angle parallel to the optical axis.

[0006] Preferably, a lens array and a coupling optical system are further provided between the pinhole aperture and the system under test, so as to match the parallel light emitted by the coupling optical system with the aperture of the optical system under test.

[0007] Preferably, the value of the incremental amount of optical fiber length in the optical fiber array is determined by the simulation accuracy of the equivalent distance.

[0008] Preferably, the optical fiber array is configured to project the light beam emitted by each optical fiber to different angles, so that the liquid crystal spatial light modulator can determine the distance information represented by the corresponding optical fiber according to the angle of the light beam.

[0009] One technical effect of the present invention is that an optical fiber array is used as a time delay device, each optical fiber in the optical fiber array has a different length and increases at a certain length interval, and a time delay is achieved by transmitting a laser in optical fibers of different lengths. A liquid crystal spatial light modulator is used as a gating device, and the phase delay function of the liquid crystal subunit is used to deflect the incident light beam to a parallel optical axis output, so as to achieve gating of an optical fiber of a specific length, thereby achieving simulation of a specific distance.

[0010] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0012] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0013] Figure 2 A schematic diagram of the correspondence between distance information and light beam angle in one embodiment of the present invention;

[0014] Figure 3 Schematic diagram of light beam deflection of a liquid crystal spatial light modulator in one embodiment of the present invention

[0015] Figure 4 A schematic diagram of the principle of a spatial filtering optical system and a pinhole aperture in one embodiment of the present invention;

[0016] Figure 5 Schematic diagram of the principle of a lens array and a coupling optical system in one embodiment of the present invention.

[0017] Explanation of the reference numerals: 1-laser, 2-fiber array coupler, 3-fiber array, 4-collimator, 5-liquid crystal spatial light modulator, 6-spatial filtering optical system, 7-pinhole aperture, 8-test system, 9-lens array, 10-coupling optical system, 11-collimator, 12-collimator. DETAILED DESCRIPTION

[0018] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0019] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0020] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0021] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0022] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0023] The present invention provides a laser three-dimensional imaging simulator, such as Figure 1 As shown, it includes a laser 1, a fiber array coupler 2, a fiber array 3 composed of fiber bundles with increasing lengths, a liquid crystal spatial light modulator 5, a spatial filtering optical system 6, a pinhole diaphragm 7 arranged on the focal plane of the spatial filtering optical system, and a test system 8, wherein the light beam emitted by the laser 1 is projected to the fiber array coupler 2 after being collimated, and enters the fiber array 3 after being decomposed; the output light of the fiber array 3 is projected to the liquid crystal spatial light modulator 5 after being collimated; among the light beams output by the liquid crystal spatial light modulator 5, the light beam passing through the pinhole diaphragm 7 is projected to the test system 8 after being collimated.

[0024] The key parts of the present invention are the optical fiber array 3, the liquid crystal spatial light modulator 4, the spatial filtering optical system 6 and the pinhole aperture 7. The optical fiber array 3 is composed of optical fibers of different lengths, the lengths of which increase in sequence with a fixed value, and the lengths of the optical fibers are used to simulate the time delay of optical signals at different distances. Figure 1 It can be seen that the different positions of the optical fiber's output end make the output light projected onto the liquid crystal spatial light modulator 4 as parallel light at different angles after collimation, and the liquid crystal spatial light modulator 4 can use the phase delay function of its liquid crystal subunit to deflect the incident light in a spatial two-dimensional angle, thereby enabling the light beam of a specific incident angle to be deflected to an angle parallel to the optical axis for output. Because the incident angle corresponds to the length of the optical fiber one-to-one, the liquid crystal spatial light modulator can be used to achieve the deflection and output of only the light beam output from the optical fiber of a certain length (i.e., a certain specific incident angle). Considering that the light beams output by each liquid crystal subunit contain parallel light at different angles, and only the light beam parallel to the optical axis is finally projected onto the test system, it is necessary to converge the parallel light beams of different angles through the spatial filtering optical system 6, set the pinhole aperture 7 at the focal plane position, only allow the central field of view to pass, and then convert the central field of view light beam into parallel light through the collimating lens 12. So far, the light beam output from the optical fiber of a specific length is selected and output in the form of a parallel light beam.

[0025] Furthermore, a lens array 9 and a coupling optical system 10 are provided between the pinhole aperture 7 and the tested system 8 to match the parallel light emitted by the coupling optical system with the aperture of the tested optical system.

[0026] Furthermore, the incremental length of the optical fiber in the optical fiber array 3 can be adjusted as needed, and the value is determined by the simulation accuracy of the equivalent distance. The optical fiber array is also configured to project the light beam emitted by each optical fiber to different angles, so that the liquid crystal spatial light modulator can determine the distance information represented by the corresponding optical fiber according to the angle of the light beam.

[0027] <Example>

[0028] The host computer receives the image to be simulated and the distance information corresponding to each pixel in the image. The distance information is used to simulate the distance between the pixel position and the device under test in the infrared scene. The host computer calculates the angle at which each liquid crystal subunit needs to deflect the light beam to achieve the simulation of the corresponding distance, and enables the liquid crystal spatial light modulator to perform the above control.

[0029] The structural diagram of this embodiment is as follows Figure 1 As shown, the working process is: the pulsed laser emitted by the laser 1 is collimated by the collimating optical system 11 and then projected to the fiber array coupler 2, the laser beam is decomposed into a 32×32 array and coupled into the fiber array 3, the length of each optical fiber in the fiber array 3 is different, and its length increases at intervals of 0.2m, that is, the fiber lengths are L, L+0.2m, L+0.4m...L+204.6m respectively, so the laser pulse emitted at the output end of the fiber array 3 produces a relative time delay, the relative time delay interval is 1ns, and the equivalent simulation distance accuracy is 0.3m.

[0030] At the output end of the optical fiber array 3, a collimating lens 4 is arranged to project the light beams output from the optical fiber array 3 as parallel light at different angles, that is, the light beams output from each optical fiber are projected at different angles, so as to achieve a one-to-one correspondence between the distance information and the light beam angles. Figure 2 shown.

[0031] The light beam emitted from the optical fiber is collimated and then projected to the liquid crystal spatial light modulator 5. The light beam covers the liquid crystal array. Each subunit on the liquid crystal spatial light modulator 5 can receive parallel light beams at different angles. The liquid crystal subunit can divide the incident light beam into a 32×32 array. By using the phase delay function of the liquid crystal, the incident light beam can be deflected in a two-dimensional space, so that the light beam with a specific incident angle can be deflected to a parallel optical axis for output, such as Figure 3 The liquid crystal subunit displays different images and can switch the output of light beams with different incident angles.

[0032] Since the light beams output by each subunit of the liquid crystal contain parallel light at different angles, and the light beam that needs to be finally projected to the receiving system is only the light beam parallel to the optical axis, a spatial filtering optical system 6 is set at the front end of the liquid crystal spatial light modulator 5. First, a lens group is used to converge the parallel light beams at different angles, and a small aperture diaphragm 7 is placed on the focal plane of the lens group to allow only the central field of view light beam to pass through. Then a collimator 12 is set to transform the central field of view light beam into parallel light, as shown in FIG. Figure 4 shown.

[0033] A lens array 9 is arranged at the exit end of the collimator 12 to converge each sub-unit light beam, so that the focus point position coincides with the focal plane of the coupling optical system 10. Then, after each point exit light beam is collimated by the coupling optical system 10, it is projected to the test system 8 in the form of parallel light, so as to achieve field matching with the test system 8 and aperture coverage, such as Figure 5 shown.

[0034] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A laser three-dimensional imaging simulator, characterized in that: The invention comprises a laser, a fiber array coupler, a fiber array composed of fiber bundles of increasing length, a liquid crystal spatial light modulator, a spatial filtering optical system, a pinhole aperture arranged on the focal plane of the spatial filtering optical system and a test system, wherein the light beam emitted by the laser is collimated and then projected to the fiber array coupler, and then decomposed and enters the fiber array; the output light of the fiber array is collimated and then projected to the liquid crystal spatial light modulator; among the light beams output by the liquid crystal spatial light modulator, the light beams passing through the pinhole aperture are collimated and then projected to the test system; the liquid crystal spatial light modulator is configured to deflect the incident light beam at a spatial two-dimensional angle through the phase delay function of the liquid crystal subunit, so as to realize the deflection of the light beam with a specified incident angle to an angle parallel to the optical axis for output; the fiber array is configured to project the light beam emitted by each optical fiber to different angles, so that the liquid crystal spatial light modulator can determine the distance information represented by the corresponding optical fiber according to the light beam angle.

2. The laser three-dimensional imaging simulator according to claim 1, characterized in that: A lens array and a coupling optical system are also arranged between the pinhole aperture and the tested system to match the parallel light emitted by the coupling optical system with the aperture of the tested optical system.

3. The laser three-dimensional imaging simulator according to claim 1, characterized in that: The value of the incremental length of the optical fiber in the optical fiber array is determined by the simulation accuracy of the equivalent distance.

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