Long-distance super-resolution three-dimensional imaging test device and method

Abstract

The present application provides a long-distance super-resolution three-dimensional imaging test device. The long-distance super-resolution three-dimensional imaging system includes a laser, a transceiver coaxial optical path part and a detector. The test device includes: a three-dimensional resolution board, an optical fiber, which is arranged in the optical path between the laser and the detector, and is used to increase the optical path between the laser and the detector to achieve long distance indoors; a parallel light pipe, which is arranged in the optical path between the three-dimensional resolution board and the transceiver coaxial optical path part, and is used to focus the light beam passing through the transceiver coaxial optical path part on the three-dimensional resolution board, and receive the echo light signal returned from the three-dimensional resolution board, and the echo light signal enters the transceiver coaxial optical path part through the parallel light pipe; a processor, based on Fisher information theory, processes the light intensity distribution data collected by the detector to obtain a Fisher information value, and evaluates the axial resolution of the long-distance super-resolution three-dimensional imaging system according to the Fisher information value.

Description

Technical Field

[0001] The present application relates to the field of optical technology, and in particular to a long-distance super-resolution three-dimensional imaging test device and method. Background Art

[0002] Hypothesis testing in statistical inference is applied to the problem of imaging resolution, using the average error of statistical decisions under the following two assumptions as a representation of the resolution of incoherent point sources: the assumption of a point source and the assumption of two incoherent point sources with a small spacing. In addition, parameter estimation in statistical inference is also a commonly used method to characterize resolution. Within the framework of parameter estimation, resolution can be measured by the accuracy of the estimate of the spacing between two point sources.

[0003] In the prior art, the evaluation of resolution mainly relies on the Rayleigh criterion. However, according to the Rayleigh criterion, when the distance between the image spot centers of two incoherent point light sources is less than the radius of the first zero point of their diffraction pattern (Airy disk), they are considered indistinguishable. Therefore, there is no objective evaluation standard for the resolution in the sub-Rayleigh region (the Rayleigh criterion believes that the incoherent point light source is not within the resolvable distance).

[0004] Therefore, it is necessary to propose a technical solution to solve the current problem of lack of objective evaluation criteria for resolution in the sub-Rayleigh region. Summary of the invention

[0005] The purpose of this application is to provide a long-distance super-resolution three-dimensional imaging test device and method, by introducing Fisher information theory to accurately evaluate the accuracy of the axial resolution of a long-distance super-resolution three-dimensional imaging system.

[0006] Based on the above purpose, the present application provides a long-distance super-resolution three-dimensional imaging test device, the test device is used to evaluate the axial resolution of the long-distance super-resolution three-dimensional imaging system, the long-distance super-resolution three-dimensional imaging system comprises a laser, a transceiver coaxial optical path part and a detector, the laser emits a light beam, the light beam passes through the transceiver coaxial optical path part to scan the imaging target and reflect to generate an echo light signal, the echo light signal passes through the transceiver coaxial optical path part to enter the detector;

[0007] The testing device comprises:

[0008] A three-dimensional resolution plate, the three-dimensional resolution plate serving as an imaging target;

[0009] An optical fiber, arranged in the optical path between the laser and the detector, for increasing the optical path between the laser and the detector;

[0010] A collimator, disposed in the optical path between the three-dimensional resolution panel and the transceiver coaxial optical path portion, for focusing the light beam passing through the transceiver coaxial optical path portion on the three-dimensional resolution panel and receiving an echo optical signal returned from the three-dimensional resolution panel, wherein the echo optical signal enters the transceiver coaxial optical path portion through the collimator;

[0011] The processor processes the light intensity distribution data collected by the detector based on Fisher information theory to obtain a Fisher information value, and evaluates the axial resolution of the long-distance super-resolution three-dimensional imaging system according to the Fisher information value.

[0012] Furthermore, the collimator comprises:

[0013] A focusing unit is arranged on the optical path between the transceiver coaxial optical path portion and the three-dimensional resolution panel, and is used to receive the light beam from the transceiver coaxial optical path portion and convert the light beam into a converging light beam;

[0014] The three-dimensional resolution panel is arranged at the focal plane of the light focusing unit.

[0015] Furthermore, the focusing unit includes at least one curved reflective element, and the curved reflective element is a concave spherical reflector or an aspherical reflector, wherein the aspherical reflector is an off-axis parabolic reflector or a toroidal reflector.

[0016] Furthermore, the transceiver coaxial optical path unit includes a transmitting optical path unit, the light beam emitted by the laser scans the three-dimensional resolution plate through the transmitting optical path unit, and the optical fiber is arranged between the laser and the transmitting optical path unit.

[0017] Furthermore, the testing device also includes:

[0018] The first focusing lens is arranged in the optical path between the laser and the optical fiber, receives and converges the light beam emitted by the laser, and the light beam emitted by the laser is coupled into the optical fiber through the first focusing lens, and the light beam enters the emission optical path unit through the optical fiber.

[0019] Furthermore, the transceiver coaxial optical path unit includes a receiving optical path unit, the receiving optical path unit receives the echo optical signal from the three-dimensional resolution panel, and the optical fiber is arranged between the detector and the receiving optical path unit.

[0020] Furthermore, the testing device also includes:

[0021] a second focusing lens, arranged in the optical path between the receiving optical path unit and the optical fiber, receiving and converging the echo optical signal, and coupling the converged echo optical signal into the optical fiber;

[0022] The third focusing lens receives and converges the echo light signal passing through the optical fiber, and couples the echo light signal into the detector.

[0023] Furthermore, the testing device also includes:

[0024] The gate control circuit is connected to the detector and is used to set the sampling frequency and single sampling duration of the detector.

[0025] Furthermore, the single sampling duration set by the gate control circuit is related to the total optical path of the laser in the test device. In a single sampling cycle, when the time is greater than t s The detector starts sampling at t s It is expressed as follows:

[0026]

[0027] Among them, L Fn represents the length of the optical fiber, L1 represents the optical path length from the laser to the detector in the test device except the optical fiber, and c represents the speed of light.

[0028] The present application also provides a method for evaluating a long-distance super-resolution three-dimensional imaging system, which is used to evaluate the axial resolution of the long-distance super-resolution three-dimensional imaging system. The method comprises the following steps:

[0029] Scanning the three-dimensional resolution plate by the long-distance super-resolution three-dimensional imaging system to collect light intensity distribution data;

[0030] Preprocessing the light intensity distribution data to remove singular points;

[0031] Normalizing the light intensity distribution data to obtain a normalized light intensity probability distribution;

[0032] The normalized light intensity probability distribution is processed based on Fisher information theory to obtain a Fisher information value, and the axial resolution of the long-distance super-resolution three-dimensional imaging system is evaluated according to the Fisher information value. The Fisher information value is expressed as follows:

[0033]

[0034] in, represents the Fisher information value, P(t) represents the normalized light intensity probability distribution, and t represents time.

[0035] The present application provides a long-distance super-resolution three-dimensional imaging test device, which uses a collimator and an optical fiber combination to simulate a long-distance effect indoors, and places a three-dimensional resolution plate at the focal plane of the collimator to measure light intensity distribution data, and based on Fisher information theory, processes the light intensity distribution data collected by the detector to obtain a Fisher information value, and evaluates the axial resolution of the long-distance super-resolution three-dimensional imaging system according to the Fisher information value, thereby achieving an accurate evaluation of the accuracy of the axial resolution of a long-distance super-resolution three-dimensional imaging system. The evaluation method provides an objective evaluation standard for the evaluation of axial resolution in the sub-Rayleigh region. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a working schematic diagram of a long-distance super-resolution three-dimensional imaging system in the prior art;

[0037] Figure 2 A schematic diagram of a three-dimensional resolution panel provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of a collimator provided in an embodiment of the present application;

[0039] Figure 4 A schematic diagram of a testing device provided in one embodiment of the present application;

[0040] Figure 5 A schematic diagram of a testing device provided in another embodiment of the present application;

[0041] Figure 6 Schematic diagram of an evaluation method for a long-distance super-resolution three-dimensional imaging system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The present invention will be described in detail below in conjunction with the specific embodiments shown in the accompanying drawings, but these embodiments do not limit the present invention. Structural, methodological, or functional changes made by ordinary technicians in the field based on these embodiments are all included in the protection scope of the present invention.

[0043] like Figure 1 As shown, it shows a schematic diagram of the operation of a long-distance super-resolution three-dimensional imaging system in the prior art. The long-distance super-resolution three-dimensional imaging system includes a transceiver coaxial optical path portion 11 and a detector 12. A laser 21 is provided, and the laser 21 can be a picosecond laser 21. When the long-distance super-resolution three-dimensional imaging system is working, the laser emitted by the laser 21 is irradiated on the imaging target surface through the transceiver coaxial optical path portion 11, and is reflected on the imaging target surface to form an echo light signal. The echo light signal returns along the original optical path and is received by the transceiver coaxial optical path portion 11. After passing through the transceiver coaxial optical path portion 11, the echo light signal enters the detector 12 and is recognized by the detector 12.

[0044] The above description is a general working method of an existing long-distance super-resolution three-dimensional imaging system. When using a long-distance super-resolution three-dimensional imaging system for imaging, according to the Rayleigh criterion, when the distance between the centers of the image spots of two incoherent point light sources is less than the radius of the first zero point of their diffraction pattern (Airy disk), they are considered to be indistinguishable. Therefore, in the sub-Rayleigh region (the Rayleigh criterion believes that the incoherent point light source is not within the distance that can be resolved), there is no objective evaluation standard for the accuracy of the axial resolution limit of the long-distance super-resolution three-dimensional imaging system. To this end, the present application provides a long-distance super-resolution three-dimensional imaging test device for evaluating the axial resolution of a long-distance super-resolution three-dimensional imaging system.

[0045] Among them, in order to provide a unified evaluation standard for the axial resolution of a long-distance super-resolution three-dimensional imaging system, when using the test device provided in the embodiment of the present application to evaluate the long-distance super-resolution three-dimensional imaging system, a unified three-dimensional resolution plate that can be used as a reference is used as the imaging target. The "axial resolution of a long-distance super-resolution three-dimensional imaging system" mentioned in the embodiment of the present application refers to the resolution of the long-distance super-resolution three-dimensional imaging system when collecting depth information of the imaging target. As an optional implementation method, the test device provided in the embodiment of the present application includes:

[0046] A three-dimensional resolution plate, the three-dimensional resolution plate serving as an imaging target;

[0047] The optical fiber is arranged in the optical path between the laser and the detector, and is used to increase the optical path between the laser and the detector;

[0048] A collimator is provided in the optical path between the three-dimensional resolution board and the transceiver coaxial optical path portion, and is used to focus the light beam passing through the transceiver coaxial optical path portion on the three-dimensional resolution board, and receive the echo light signal returned from the three-dimensional resolution board, and the echo light signal enters the transceiver coaxial optical path portion through the collimator;

[0049] The processor processes the light intensity distribution data collected by the detector based on Fisher information theory to obtain Fisher information values, and evaluates the axial resolution of the long-distance super-resolution three-dimensional imaging system according to the Fisher information values.

[0050] like Figure 2 As shown, it shows a schematic diagram of a three-dimensional resolution board provided in an embodiment of the present application. As an optional implementation, the three-dimensional resolution board provided in an embodiment of the present application is an object with an uneven measured surface, and the measured surface includes a combination of multiple periodic structures. It is convenient to collect depth information when testing a long-distance super-resolution three-dimensional imaging system.

[0051] like Figure 3As shown, it shows a schematic diagram of a collimator 23 provided in an embodiment of the present application. As an optional implementation, the collimator 23 provided in an embodiment of the present application includes a focusing unit 231. The focusing unit 231 is arranged on the optical path between the transceiver coaxial optical path portion 11 and the three-dimensional resolution board, and is used to receive the light beam from the transceiver coaxial optical path portion 11 and convert the light beam into a converging light beam. In addition, the three-dimensional resolution board is arranged at the focal plane of the focusing unit.

[0052] As an optional implementation, the light focusing unit 231 includes at least one curved reflective element. For example, the curved reflective element is a concave spherical reflector or an aspherical reflector.

[0053] As an optional implementation, the aspheric reflector may be an off-axis parabolic reflector or a toroidal reflector.

[0054] like Figure 3 As shown, as an optional implementation, the collimator 23 provided in the embodiment of the present application may further include at least one plane reflective element for adjusting the light path. Specifically, in the embodiment of the present application, the collimator 23 includes a first plane reflective element 232, and the first plane reflective element 232 is arranged in the light path between the focusing unit 231 and the three-dimensional resolution panel. By adjusting the position and / or angle of the first plane reflective element 232 in the light path, the focus position of the convergent light beam emitted by the focusing unit 231 can be adjusted.

[0055] In the embodiment of the present application, only an exemplary embodiment is provided in which the collimator 23 includes a planar reflective element. However, those skilled in the art should know that it is possible to adjust the position of the focus of the focusing unit 231 by one or more planar reflective elements. Similarly, in the embodiment of the present application, only an exemplary embodiment is provided in which the focusing unit 231 includes a curved reflective element. However, those skilled in the art should know that focusing can be achieved by combining a curved reflective element or multiple curved reflective elements.

[0056] The working principle of the collimator 23 provided in the embodiment of the present application can refer to the existing long-distance super-resolution three-dimensional imaging system. As mentioned above, for the long-distance super-resolution three-dimensional imaging system, the laser emitted by the transceiver coaxial optical path part 11 is irradiated on the surface of the three-dimensional resolution plate, and is reflected on the surface of the three-dimensional resolution plate to form an echo light signal, and the echo light signal returns along the original optical path and enters the transceiver coaxial optical path part 11.

[0057] According to the above description, it can be understood that when a collimator 23 is arranged between the transceiver coaxial optical circuit portion 11 and the three-dimensional resolution panel in the embodiment of the present application, the light beam emitted from the transceiver coaxial optical circuit portion 11 enters the collimator 23, is focused by the focusing unit 231 and then irradiates the surface of the three-dimensional resolution panel, or is first focused by the focusing unit 231 and then the focal position is adjusted by a planar reflective element so that the focused light beam is irradiated on the surface of the three-dimensional resolution panel.

[0058] The laser irradiates the surface of the three-dimensional resolution plate and reflects to form an echo light signal. The echo light signal returns along the original optical path and enters the collimator 23. Since the three-dimensional resolution plate is located at the focus of the focusing unit 231, the echo light signal is collimated after being reflected by the focusing unit 231. The collimated echo light signal is received by the transceiver coaxial optical path unit 11 and finally enters the detector 12.

[0059] As an optional implementation method, the present application also sets an optical fiber 22 in the optical path between the laser 21 and the detector 12, so as to increase the optical path between the laser 21 and the detector 12, thereby simulating a long-distance effect in an indoor environment. Therefore, the test device provided by the present application can conveniently evaluate the axial resolution of a long-distance imaging device indoors.

[0060] For the existing long-distance imaging device, its transceiver coaxial optical path unit 11 can be further subdivided into a transmitting optical path unit 111 and a receiving optical path unit 112. Specifically, when the long-distance super-resolution three-dimensional imaging system is working, the laser emitted by the laser 21 is irradiated on the surface of the three-dimensional resolution board through the transmitting optical path unit 111 in the transceiver coaxial optical path unit 11, and is reflected on the surface of the three-dimensional resolution board to form an echo optical signal. The echo optical signal returns along the original optical path and is received by the receiving optical path unit 112 in the transceiver coaxial optical path unit 11. After passing through the transceiver coaxial optical path unit 11, the echo optical signal enters the detector 12 and is recognized by the detector 12.

[0061] Therefore, referring to the optical path of the long-distance super-resolution three-dimensional imaging system when it is working, as an optional implementation method, the optical fiber 22 can be arranged between the laser 21 and the transmitting optical path unit 111, or the optical fiber 22 can also be arranged between the detector 12 and the receiving optical path unit 112.

[0062] like Figure 4 , which shows a schematic diagram of a test device provided by an embodiment of the present application. Specifically, the optical fiber 22 is arranged between the laser 21 and the emission optical path unit 111. The test device also includes: a first focusing lens 24.

[0063] The first focusing lens 24 is disposed in the optical path between the laser 21 and the optical fiber 22 to receive and converge the light beam emitted by the laser 21. The light beam emitted by the laser 21 is coupled into the optical fiber 22 through the first focusing lens 24, and the light beam enters the emission optical path unit 111 through the optical fiber 22.

[0064] Figure 4 Only the emission optical path portion of the complete optical path when the test device is working is shown. It should be known that in this embodiment of the present application, when the test device is working, the laser emitted by the laser 21 first passes through the first focusing lens 24, and the first focusing lens 24 converges the laser and couples it into one end of the optical fiber 22, and then emits it from the other end of the optical fiber 22 into the emission optical path unit 111. Then, the light beam emitted from the emission optical path unit 111 enters the collimator 23, and is focused onto the surface of the three-dimensional resolution board by the focusing unit 231 in the collimator 23. On the surface of the three-dimensional resolution board, the light beam is reflected to form an echo optical signal, and the echo optical signal returns along the original optical path through the collimator 23, and is received by the receiving optical path unit 112 in the transceiver coaxial optical path unit 11. After passing through the transceiver coaxial optical path unit 11, the echo optical signal enters the detector 12 and is recognized by the detector 12.

[0065] As an optional implementation, the length of the optical fiber 22 can be selected according to demand. For example, the optical fiber 22 can be a multi-mode optical fiber 22 with a length of 20 km, 50 km, or 100 km.

[0066] like Figure 5 , which shows a schematic diagram of a test device provided by another embodiment of the present application. Specifically, the optical fiber 22 is arranged between the detector 12 and the receiving optical path unit 112. The test device also includes: a second focusing lens 26 and a third focusing lens 27.

[0067] The second focusing lens 26 is disposed in the optical path between the receiving optical path unit 112 and the optical fiber 22, receives and converges the echo optical signal, and couples the converged echo optical signal into the optical fiber 22;

[0068] The third focusing lens 27 is used to receive and converge the echo light signal passing through the optical fiber 22 , and couple the echo light signal into the detector 12 .

[0069] Figure 5Only the receiving optical path portion of the complete optical path when the test device is working is shown. It should be known that in this embodiment of the present application, when the test device is working, the laser emitted by the laser 21 passes through the transmitting optical path unit 111 in the transceiver coaxial optical path part 11, is focused by the focusing unit 231 in the collimator 23, and is irradiated on the surface of the three-dimensional resolution plate, and is reflected on the surface of the three-dimensional resolution plate to form an echo optical signal. The echo optical signal returns along the original optical path through the collimator 23 and is received by the receiving optical path unit 112 in the transceiver coaxial optical path part 11. After passing through the receiving optical path unit 112, the echo optical signal is converged by the second focusing lens 26, and the converged echo optical signal is coupled into one end of the optical fiber 22. The echo optical signal emitted from the other end of the optical fiber 22 is converged by the third focusing lens 27 and the echo optical signal is coupled into the detector 12.

[0070] like Figure 5 As shown, one or more planar reflective elements may be provided between the detector 12 and the receiving optical path unit 112 to adjust the optical path, thereby effectively utilizing the indoor space.

[0071] Based on the above description, the optical path structure of the test device provided in the embodiment of the present application when working is described in detail. The following will further explain how to use the test device to evaluate the long-distance super-resolution three-dimensional imaging system.

[0072] As an optional implementation, the test device provided in the embodiment of the present application further includes a processor. The processor processes the light intensity distribution data collected by the detector 12 based on the Fisher information theory to obtain a Fisher information value, and evaluates the axial resolution of the long-distance super-resolution three-dimensional imaging system according to the Fisher information value.

[0073] Specifically, the test device provided in the embodiment of the present application is combined with the long-distance super-resolution three-dimensional imaging system to be evaluated to form a complete experimental optical path, and the laser 21 is started to scan the three-dimensional resolution plate located at the focal plane of the parallel light tube 23. The generated echo light signal is finally received by the detector 12.

[0074] As an optional implementation method, the detector 12 provided in the embodiment of the present application may adopt a single photon avalanche diode to improve the sensitivity of the detector 12 .

[0075] As an optional implementation, the test device provided in the embodiment of the present application further includes a gate control circuit 29. The gate control circuit 29 is connected to the detector 12 and is used to set the sampling frequency and single sampling duration of the detector 12.

[0076] Specifically, the sampling frequency and single sampling duration of the detector 12 can be designed according to the total optical path of the laser in the test device.

[0077] In the test setup, the total optical path length of the laser can be expressed as follows:

[0078] L=L1+L Fn

[0079] Among them, L Fn represents the length of the optical fiber 22, and L1 represents the optical path length from the laser 21 to the detector 12 in the test device except the optical fiber 22.

[0080] Therefore, the time taken for the laser to travel from the laser 21 to the detector 12 is approximately:

[0081] Among them, L Fn represents the length of the optical fiber 22, L1 represents the optical path length from the laser 21 to the detector 12 in the test device except the optical fiber 22, and c represents the speed of light.

[0082] As an optional implementation, in the embodiment of the present application, the detection is turned off when the laser 21 emits laser, and the detection is turned on after the laser is completely emitted. s Up to 10t s This avoids detecting local echoes caused by local optical devices.

[0083] As an optional implementation, the rising edge signal of the laser 21 can be used as a trigger signal to implement time gating for the detector 12. In a single cycle, the rising edge signal of the laser 21 can be used as a trigger signal to implement time gating for the detector 12. s The detector 12 is turned off during the time period and turned on at other times to reduce the entry of diffuse reflected light.

[0084] As an optional implementation, in an embodiment of the present application, the processor includes:

[0085] A preprocessing module is used to preprocess the light intensity distribution data and remove singular points;

[0086] A normalization processing module, which is used to perform normalization processing on the light intensity distribution data to obtain a normalized light intensity probability distribution;

[0087] Fisher information processing module processes the normalized light intensity probability distribution based on Fisher information theory to obtain the Fisher information value. The axial resolution of the long-distance super-resolution 3D imaging system is evaluated according to the Fisher information value. The Fisher information value is expressed as follows:

[0088]

[0089] in, represents the Fisher information value, P(t) represents the normalized light intensity probability distribution, and t represents time.

[0090] like Figure 6 As shown, the present application also provides a long-distance super-resolution three-dimensional imaging test method for evaluating the axial resolution of a long-distance super-resolution three-dimensional imaging system.

[0091] As an optional implementation, the detector 12 collects light intensity distribution data;

[0092] By preprocessing the light intensity distribution data and removing singular points, the time distribution histogram I(θ, t) of the light intensity distribution data can be obtained.

[0093] Wherein, θ represents the scanning angle of the galvanometer when the long-distance super-resolution 3D imaging system scans the surface of the 3D resolution plate, t represents the laser flight time, and I is the number of single photons counted corresponding to θ and t.

[0094] The light intensity distribution data is normalized to obtain the normalized light intensity probability distribution. Specifically, the normalized light intensity probability distribution can be expressed as follows:

[0095]

[0096] Where I represents the number of single photons counted corresponding to θ and t, I MAX Represents the maximum number of single photons counted corresponding to θ and t.

[0097] The normalized light intensity probability distribution is processed based on Fisher information theory to obtain a Fisher information value, and the axial resolution of the long-distance super-resolution three-dimensional imaging system is evaluated according to the Fisher information value.

[0098] Specifically, taking the logarithm of the normalized light intensity probability distribution function yields: ln P(t).

[0099] Then take the second-order partial derivative of ln P(t) with respect to Δt:

[0100] Then, the Fisher information value is expressed as follows:

[0101]

[0102] in, represents the Fisher information value, and P(t) represents the normalized light intensity probability distribution.

[0103] The inverse of the Fisher information value is: The inverse can be expressed as the error value of the axial resolution limit of the long-distance super-resolution three-dimensional imaging system. The smaller the value, that is, the larger the Fisher information value, indicates that the axial resolution limit measured by the long-distance super-resolution three-dimensional imaging system is more accurate.

[0104] According to the above description, the present application provides a long-distance super-resolution three-dimensional imaging test device, which uses a collimator 23 and an optical fiber 22 to simulate a long-distance effect indoors, and places a three-dimensional resolution plate at the focal plane of the collimator 23 to measure the light intensity distribution data, and based on the Fisher information theory, the light intensity distribution data collected by the detector 12 is processed to obtain the Fisher information value, and the axial resolution of the long-distance super-resolution three-dimensional imaging system is evaluated according to the Fisher information value, thereby realizing a precise evaluation of the accuracy of the axial resolution of a long-distance super-resolution three-dimensional imaging system. This evaluation method provides an objective evaluation standard for the evaluation of the axial resolution in the sub-Rayleigh region.

[0105] The above disclosure is only the preferred embodiment of the present invention, but it is not used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that without departing from the spirit and scope of the present invention and the attached claims, changes, modifications, substitutions, combinations, and simplifications should all be equivalent replacement methods and still fall within the scope of the invention.

Claims

1. A long-distance super-resolution three-dimensional imaging test device, the test device is used to evaluate the axial resolution of a long-distance super-resolution three-dimensional imaging system, the long-distance super-resolution three-dimensional imaging system comprises a laser, a transceiver coaxial optical path part and a detector, the laser emits a light beam, the light beam passes through the transceiver coaxial optical path part to scan an imaging target and reflects to generate an echo light signal, the echo light signal passes through the transceiver coaxial optical path part and enters the detector; It is characterized in that The testing device comprises: A three-dimensional resolution plate, the three-dimensional resolution plate serving as an imaging target; An optical fiber, arranged in the optical path between the laser and the detector, for increasing the optical path between the laser and the detector; A collimator, disposed in the optical path between the three-dimensional resolution panel and the transceiver coaxial optical path portion, for focusing the light beam passing through the transceiver coaxial optical path portion on the three-dimensional resolution panel and receiving an echo optical signal returned from the three-dimensional resolution panel, wherein the echo optical signal enters the transceiver coaxial optical path portion through the collimator; The processor processes the light intensity distribution data collected by the detector based on Fisher information theory to obtain a Fisher information value, and evaluates the axial resolution of the long-distance super-resolution three-dimensional imaging system according to the Fisher information value.

2. The long-distance super-resolution three-dimensional imaging test device according to claim 1, characterized in that: The collimator comprises: A focusing unit is arranged on the optical path between the transceiver coaxial optical path portion and the three-dimensional resolution panel, and is used to receive the light beam from the transceiver coaxial optical path portion and convert the light beam into a converging light beam; The three-dimensional resolution panel is arranged at the focal plane of the light focusing unit.

3. The long-distance super-resolution three-dimensional imaging test device according to claim 2, characterized in that: The focusing unit comprises at least one curved reflective element, and the curved reflective element is a concave spherical reflector or an aspherical reflector, wherein the aspherical reflector is an off-axis parabolic reflector or a toroidal reflector.

4. According to the long-distance super-resolution three-dimensional imaging test device of claim 1, the transceiver coaxial optical path portion comprises a transmitting optical path unit, and the light beam emitted by the laser scans the three-dimensional resolution plate through the transmitting optical path unit, characterized in that: The optical fiber is arranged between the laser and the emission optical path unit.

5. The long-distance super-resolution three-dimensional imaging test device according to claim 4, characterized in that: The testing device also includes: The first focusing lens is arranged in the optical path between the laser and the optical fiber, receives and converges the light beam emitted by the laser, and the light beam emitted by the laser is coupled into the optical fiber through the first focusing lens, and the light beam enters the emission optical path unit through the optical fiber.

6. According to the long-distance super-resolution three-dimensional imaging test device of claim 1, the transceiver coaxial optical path unit comprises a receiving optical path unit, and the receiving optical path unit receives the echo optical signal from the three-dimensional resolution plate, characterized in that: The optical fiber is arranged between the detector and the receiving optical path unit.

7. The long-distance super-resolution three-dimensional imaging test device according to claim 6, characterized in that: The testing device also includes: a second focusing lens, arranged in the optical path between the receiving optical path unit and the optical fiber, receiving and converging the echo optical signal, and coupling the converged echo optical signal into the optical fiber; The third focusing lens receives and converges the echo light signal passing through the optical fiber, and couples the echo light signal into the detector.

8. The long-distance super-resolution three-dimensional imaging test device according to claim 1, characterized in that: The testing device also includes: The gate control circuit is connected to the detector and is used to set the sampling frequency and single sampling duration of the detector.

9. The long-distance super-resolution three-dimensional imaging test device according to claim 8, characterized in that: The single sampling duration set by the gate control circuit is related to the total optical path of the laser in the test device. In a single sampling cycle, when the time is greater than t s The detector starts sampling at t s It is expressed as follows: Among them, L Fn represents the length of the optical fiber, L1 represents the optical path length from the laser to the detector in the test device except the optical fiber, and c represents the speed of light.

10. A long-distance super-resolution three-dimensional imaging test method for evaluating the axial resolution of a long-distance super-resolution three-dimensional imaging system, characterized in that: The method comprises the following steps: Scanning the three-dimensional resolution plate by the long-distance super-resolution three-dimensional imaging system to collect light intensity distribution data; Preprocessing the light intensity distribution data to remove singular points; Normalizing the light intensity distribution data to obtain a normalized light intensity probability distribution; The normalized light intensity probability distribution is processed based on Fisher information theory to obtain a Fisher information value, and the axial resolution of the long-distance super-resolution three-dimensional imaging system is evaluated according to the Fisher information value. The Fisher information value is expressed as follows: in, represents the Fisher information value, P(t) represents the normalized light intensity probability distribution, and t represents time.

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