A laser detection system capable of realizing a specified size energy uniform distribution image point

Abstract

This invention relates to the field of optical imaging system technology, specifically a laser detection system capable of achieving uniform energy distribution of image points of a specified size. The system includes a laser detection structure comprising a filter, a first lens, a second lens, a third lens, and a fourth lens. The filter to the fourth lens are arranged sequentially from the object surface of the laser detection structure toward the imaging surface of the laser detection structure in numerical order. The laser detection structure is used to image the light beam onto the detection surface. This invention addresses the specific requirements of laser detection regarding the size and energy uniformity of the target image points. Based on the principle of uniformity of entrance pupil and image point energy in optical systems, it proposes a mapping mode between the position of any ray at the entrance pupil and the intersection point of that ray on the image surface. Based on this mapping mode, an optimization design evaluation function for the laser detection system is constructed. Under the condition of a reasonable initial structure, the optimized design of a laser detection system with uniform energy distribution of image points of a specified size can be achieved.

Description

Technical Field

[0001] This invention relates to a laser detection system, and more particularly to a laser detection system capable of achieving uniform energy distribution of image points of a specified size, belonging to the field of optical imaging system technology. Background Technology

[0002] The design requirements for laser tracking and detection optical systems require that the laser signal scattered from an ideal target be used to form a light spot of a specified diameter with uniform energy distribution on the image plane of the optical system.

[0003] In traditional optical system design, for an ideal object point, the goal is to form the smallest possible spot on the image plane based on the principle of minimizing aberrations. The energy of this spot typically exhibits a Gaussian distribution, meaning high energy in the center and low energy around the edges. This fails to meet the requirement of forming a spot of a specified diameter with uniform energy distribution on the image plane. Although defocusing methods can be used in traditional optical design to make the spot diameter on the image plane meet the requirements, the energy distribution remains Gaussian, failing to meet the need for uniform distribution.

[0004] Therefore, it is urgent to improve the laser detection system with uniformly distributed image points to solve the above-mentioned problems. Summary of the Invention

[0005] The purpose of this invention is to provide a laser detection system that can achieve uniform energy distribution of image points of a specified size. This method addresses the special requirements of laser detection for the size and energy uniformity of target image points. Based on the principle of consistency between the entrance pupil of the optical system and the energy uniformity of image points, it proposes a mapping mode between the position of any ray at the entrance pupil and the intersection point of that ray on the image plane. Based on this mapping mode, an evaluation function for the optimization design of the laser detection system is constructed. Under the condition of a reasonable initial structure, the optimization design of a laser detection system with uniform energy distribution of image points of a specified size can be achieved.

[0006] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0007] A laser detection system capable of achieving uniform energy distribution of image points of a specified size includes a laser detection structure, wherein the laser detection structure includes a filter, a first lens, a second lens, a third lens, and a fourth lens;

[0008] The principal optical axes of the first lens, the second lens, the third lens, and the fourth lens are on the same horizontal axis, and a detection surface is provided on one side of the fourth lens;

[0009] The filter to the fourth lens are arranged sequentially from the object surface of the laser detection structure toward the imaging surface of the laser detection structure in numerical order, and the laser detection structure is used to image the light beam on the detection surface.

[0010] Preferably, the filter is a narrowband filter used for filtering light, the filter has a thickness of 4mm, and the filter is a filter made of K9 glass.

[0011] Preferably, the side of the first lens near the filter has a convex object surface, and the first lens has positive refractive power.

[0012] Preferably, the second lens corresponds to the first lens, the second lens has an object-side surface that protrudes along the optical axis and an image-side surface that is recessed along the optical axis, and the second lens has negative refractive power.

[0013] Preferably, the third lens has positive refractive power and has a concave object surface and a convex image surface.

[0014] Preferably, the fourth lens has a protruding square surface corresponding to the third lens.

[0015] Preferably, the first lens to the fourth lens are all spherical lenses made of H-ZF52 glass.

[0016] Preferably, the length of the laser detection structure is 105mm, the entrance pupil is 100mm, and the back intercept is 21.96mm;

[0017] The filter has an aperture of 104mm and a focal length of 76.38mm.

[0018] Preferably, the design method for the laser detection system is as follows:

[0019] Let the field of view corresponding to the tracked ray be α, the focal length of the optical system be f, the entrance pupil diameter be D, and the diameter of the image point on the image plane be d. Assume that the ray is located in the meridional plane and the position of the ray at the entrance pupil is x.

[0020] When the optical system is a single-image system or an odd-order imaging system, the position y of the ray on the image plane can be expressed as:

[0021]

[0022] When the optical system is a secondary imaging system or an even-order imaging system, the position y of the ray on the image plane can be expressed as:

[0023]

[0024] For n rays within a field of view of angle α, let their positions at the entrance pupil be x. i After ray tracing, the position where each ray reaches the image plane is h. i ;

[0025] When the optical system is a single-imaging system or an odd-order imaging system, the optimization evaluation function can be expressed as:

[0026]

[0027] When the optical system is a secondary imaging system or an even-order imaging system, the optimization evaluation function can be expressed as:

[0028]

[0029] By using the above-mentioned optimization evaluation function, when the evaluation function value reaches its minimum, the optimized design of a laser detection system with uniformly distributed energy image points of a specified size can be achieved.

[0030] Preferably, the wavelength is 1064nm, the aperture of the receiving lens is 100mm, the receiving field of view is 2W=3, and the diffusion diameter of the target spot at infinity is 2mm0.1mm.

[0031] The present invention has at least the following beneficial effects:

[0032] This method addresses the specific requirements of laser detection for target image size and energy uniformity. Based on the principle of uniformity of entrance pupil and image energy in optical systems, it proposes a mapping mode between the position of any ray at the entrance pupil and the intersection point of that ray on the image plane. Based on this mapping mode, an evaluation function for the optimization design of the laser detection system is constructed. Under the condition of a reasonable initial structure, the optimization design of a laser detection system with uniformly distributed energy of a specified size can be achieved. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0034] Figure 1 This is a diagram of the laser detection structure of the present invention;

[0035] Figure 2 This is a structural diagram of the optical system of the present invention;

[0036] Figure 3 This is a dot diagram of the optical system of the present invention;

[0037] Figure 4 This is a graph showing the relationship between the spot energy and spot radius at a 0-degree field of view in this invention.

[0038] Figure 5 This is a diagram showing the relationship between the spot energy and spot radius of the 1.05-degree half-field of view of the present invention;

[0039] Figure 6 This is a diagram showing the relationship between the spot energy and spot radius of the 1.5-degree half-field of view of the present invention;

[0040] Figure 7 This is a schematic diagram of the 0-degree field-of-view light spot distribution of the present invention;

[0041] Figure 8 This is a schematic diagram of the 1-degree field-of-view light spot distribution of the present invention;

[0042] Figure 9 This is a schematic diagram of the 1.5-degree half-field-of-view light spot distribution of the present invention.

[0043] In the figure, 1-laser detection structure, 101-filter, 102-first lens, 103-second lens, 104-third lens, 105-fourth lens, 2-detection surface. Detailed Implementation

[0044] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0045] like Figures 1-9 As shown, the laser detection system provided in this embodiment, which can realize uniform energy distribution of image points of a specified size, includes a laser detection structure 1. The laser detection structure 1 includes a filter 101, a first lens 102, a second lens 103, a third lens 104, and a fourth lens 105.

[0046] The principal optical axes of the first lens 102, the second lens 103, the third lens 104 and the fourth lens 105 are on the same horizontal axis, and a detection surface 2 is provided on one side of the fourth lens 105.

[0047] The filters 101 to the fourth lens 105 are arranged in numerical order from the object surface of the laser detection structure 1 toward the imaging surface of the laser detection structure 1. The laser detection structure 1 is used to image the light beam onto the detection surface 2.

[0048] This method addresses the specific requirements of laser detection for target image size and energy uniformity. Based on the principle of uniformity of entrance pupil and image energy in optical systems, it proposes a mapping mode between the position of any ray at the entrance pupil and the intersection point of that ray on the image plane. Based on this mapping mode, an evaluation function for the optimization design of the laser detection system is constructed. Under the condition of a reasonable initial structure, the optimization design of a laser detection system with uniformly distributed energy of a specified size can be achieved.

[0049] Furthermore, such as Figure 1As shown, filter 101 is a narrowband filter. Filter 101 is used to filter light. The thickness of filter 101 is 4mm. Filter 101 is a filter made of K9 glass and has a certain light filtering function.

[0050] The first lens 102 has a protruding object surface on one side near the filter 101, and the first lens 102 has positive refractive power;

[0051] The second lens 103 corresponds to the first lens 102. The second lens 103 has an object-side surface that protrudes along the optical axis and an image-side surface that is recessed along the optical axis. The second lens 103 has negative refractive power.

[0052] The third lens 104 has positive refractive power and has a concave object surface and a convex image surface.

[0053] The fourth lens 105 has a protruding square surface corresponding to the third lens 104;

[0054] The first lens 102 to the fourth lens 105 are all spherical lenses made of H-ZF52 glass. The length of the laser detection structure 1 is 105mm, the entrance pupil is 100mm, the back cutoff is 21.96mm, the filter 101 has an aperture of 104mm and a focal length of 76.38mm.

[0055] For a typical laser detection optical system, the energy distribution of a laser signal from a certain field of view is uniform at the entrance pupil of the optical system. Since it is required that the energy distribution of the signal from this field of view at the image points on the image plane is also uniform, based on the principle of uniformity of energy at the entrance pupil and image points of the optical system, given the position of any ray of light at the entrance pupil of the optical system in a certain field of view, the light can be concentrated on the detection surface 2 by the continuous refraction of the light through the first lens 102, the second lens 103, the third lens 104 and the fourth lens 105. At the same time, by designing a method, the position of the ray on the image plane can be obtained.

[0056] The specific design method for the laser detection system is as follows:

[0057] Let the field of view corresponding to the tracked ray be α, the focal length of the optical system be f, the entrance pupil diameter be D, and the diameter of the image point on the image plane be d. Assume that the ray is located in the meridional plane and the position of the ray at the entrance pupil is x. When the intersection of the ray and the entrance pupil plane is above the optical axis, x > 0; otherwise, x < 0.

[0058] When the optical system is a single-image system or an odd-order imaging system, the position y of the ray on the image plane can be expressed as:

[0059]

[0060] When the optical system is a secondary imaging system or an even-order imaging system, the position y of the ray on the image plane can be expressed as:

[0061]

[0062] For n rays within a field of view of angle α, let their positions at the entrance pupil be x. i i = 1, 2, ..., n, and the position h where each ray reaches the image plane after ray tracing is... i i = 1, 2, ..., n;

[0063] When the optical system is a single-imaging system or an odd-order imaging system, the optimization evaluation function can be expressed as:

[0064]

[0065] When the optical system is a secondary imaging system or an even-order imaging system, the optimization evaluation function can be expressed as:

[0066]

[0067] By using the above-mentioned optimization evaluation function, when the evaluation function value reaches its minimum, the optimized design of a laser detection system with uniformly distributed energy image points of a specified size can be achieved.

[0068] The wavelength is 1064nm, the aperture of the receiving lens is 100mm, the receiving field of view is 2W=3, and the diffusion diameter of the light spot at infinity is 2mm0.1mm.

[0069] The system's point graph is as follows Figure 3 As shown, the spot diameter at 0 field of view is 2 mm, the spot diameter at 1.05 half field of view is 2.02 mm, and the spot diameter at 1.5 half field of view is 1.992 mm.

[0070] Central energy distribution as Figure 4 , Figure 5 as well as Figure 6 As shown, the optical system weighs 753.59 grams;

[0071] The uniformity of the light spot can be analyzed using the American-imported software ASAP. Simulation calculations show that the uniformity of the light spot at 0 field of view is as follows: Figure 7 As shown, the uniformity of the light spot can reach over 90%. The uniformity of the light spots at 1 and 1.5 half-field of view are respectively as follows: Figure 8 , 9 As shown, the uniformity of the light spot can reach over 80%.

[0072] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0073] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes that element.

[0074] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A laser detection system capable of achieving uniform energy distribution of image points of a specified size, comprising a laser detection structure (1), characterized in that, The laser detection structure (1) includes a filter (101), a first lens (102), a second lens (103), a third lens (104), and a fourth lens (105). The principal optical axes of the first lens (102), the second lens (103), the third lens (104), and the fourth lens (105) are on the same horizontal axis, and a detection surface (2) is provided on one side of the fourth lens (105). The filter (101) to the fourth lens (105) are arranged in numerical order from the object surface of the laser detection structure (1) toward the imaging surface of the laser detection structure (1), and the laser detection structure (1) is used to image the light beam on the detection surface (2). The filter (101) is a narrowband filter, the filter (101) is used to filter light, the filter (101) has a thickness of 4mm, and the filter (101) is a filter made of K9 glass; The first lens (102) to the fourth lens (105) are all spherical lenses made of H-ZF52 glass; The laser detection structure (1) has a length of 105 mm, an entrance pupil of 100 mm, and a back intercept of 21.96 mm. The filter (101) has an aperture of 104 mm and a focal length of 76.38 mm. The design method for the laser detection system is as follows: Let the field of view corresponding to the tracked ray be . The focal length of the optical system is The diameter of the entrance pupil is The diameter of the image point on the image plane is Assuming the ray is located in the meridional plane, the position of the ray at the entrance pupil is... When the point of intersection of the ray and the entrance pupil is above the optical axis, >0, otherwise <0; When the optical system is a single-image system or an odd-order imaging system, the position of the light rays on the image plane It can be represented as: ； When the optical system is a secondary imaging system or an even-order imaging system, the position of the light rays on the image plane It can be represented as: ； For the field of view angle is Let n rays within the entrance pupil be denoted by . After ray tracing, the position where each ray reaches the image plane is... ; When the optical system is a single-imaging system or an odd-order imaging system, the optimization evaluation function can be expressed as: ； When the optical system is a secondary imaging system or an even-order imaging system, the optimization evaluation function can be expressed as: 。 2. The laser detection system according to claim 1, which can realize image points with uniform energy distribution of a specified size, is characterized in that: The first lens (102) has a convex object surface on one side near the filter (101), and the first lens (102) has positive refractive power.

3. A laser detection system capable of realizing uniform energy distribution image points of a specified size according to claim 1, characterized in that: The second lens (103) corresponds to the first lens (102). The second lens (103) has an object surface that protrudes along the optical axis and an image surface that is recessed along the optical axis. The second lens (103) has negative refractive power.

4. A laser detection system capable of realizing uniform energy distribution image points of a specified size according to claim 1, characterized in that: The third lens (104) has positive refractive power and has a concave object surface and a convex image surface.

5. A laser detection system capable of realizing uniform energy distribution image points of a specified size according to claim 1, characterized in that: The fourth lens (105) has a protruding square surface corresponding to the third lens (104).

6. A laser detection system capable of realizing uniform energy distribution image points of a specified size according to claim 1, characterized in that: The wavelength is 1064nm, the aperture of the receiving lens is 100mm, the receiving field of view is 2W=3, and the diffusion diameter of the target spot at infinity is 2mm±0.1mm.

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