Blocking-free two-reflection laser antenna with real exit pupil

Abstract

The invention discloses an unobstructed secondary reflection laser antenna with a real exit pupil. The unobstructed secondary reflection laser antenna comprises a protection window, a reflective off-axis secondary reflection optical antenna and a fast reflection mirror, wherein the parallel light reaches the reflective off-axis secondary reflective optical antenna through the protection window, small-aperture parallel light is obtained through the reflective off-axis secondary reflective optical antenna, and the small-aperture parallel light is reflected out through the fast reflective mirror. The method has the advantages of being high in link building efficiency, high in reliability and convenient to install and adjust.

Description

Technical Field

[0001] This invention belongs to the field of laser antenna technology, and particularly relates to a dual-reflection laser antenna with an unobstructed real exit pupil. Background Technology

[0002] Optical antennas are the core components of laser communication terminals. Their main functions are: to expand the aperture of the transmitted collimated beam and compress the divergence angle of the transmitted beam; and to receive optical signals transmitted from another terminal, compressing the aperture of the receiving band and providing a collimated beam for the back-end receiving optical path. Currently, the optical antenna designs of laser communication projects both domestically and internationally largely draw inspiration from astronomical telescopes, primarily using transmission-type optical systems and coaxial catadioptric optical systems. For transmission-type antennas, due to the high energy of the laser at the transmitting end, photothermal and photochemical effects can lead to problems such as glass thermal deformation and decreased transmittance, affecting the lifespan of the entire system. For coaxial catadioptric optical antennas, because the laser wavefront has a Gaussian distribution, the central part where energy is concentrated can be blocked by the central obstruction of the optical system, causing energy loss. This requires increasing the laser power or performing laser beam shaping, but this increases the power consumption, size, and weight of the entire system. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide an unobstructed dual-reflection laser antenna with a real exit pupil, which has the advantages of high link establishment efficiency, high reliability and convenient assembly and adjustment.

[0004] The objective of this invention is achieved through the following technical solution: an unobstructed dual-reflector laser antenna with a real exit pupil, comprising: a protective window, a reflective off-axis dual-reflector optical antenna, and a fast-reflecting mirror; wherein, parallel light passes through the protective window to reach the reflective off-axis dual-reflector optical antenna, and after passing through the reflective off-axis dual-reflector optical antenna, small-aperture parallel light is obtained, and the small-aperture parallel light is reflected out by the fast-reflecting mirror.

[0005] In the aforementioned unobstructed dual-reflection laser antenna with a real exit pupil, the protective window is a glass plate.

[0006] In the above-mentioned unobstructed dual-reflector laser antenna with a real exit pupil, the reflective off-axis dual-reflector optical antenna adopts an off-axis reflection optical configuration.

[0007] In the aforementioned unobstructed dual-mirror laser antenna with a real exit pupil, the reflective off-axis dual-mirror optical antenna includes a primary mirror and a secondary mirror; wherein, both the primary mirror and the secondary mirror are parabolic surfaces; and the focal point of the primary mirror and the focal point of the secondary mirror coincide.

[0008] In the aforementioned unobstructed dual-mirror antenna with a real exit pupil, the relationship between the vertex radius of curvature of the primary mirror and the vertex radius of curvature of the secondary mirror is obtained by the following formula: ; Where R1 is the vertex radius of curvature of the primary mirror, R2 is the vertex radius of curvature of the secondary mirror, and α is the compression ratio of the laser antenna.

[0009] In the aforementioned unobstructed dual-mirror laser antenna with a real exit pupil, the distance between the primary mirror and the secondary mirror is obtained by the following formula: ; Where R1 is the vertex curvature radius of the primary mirror, R2 is the vertex curvature radius of the secondary mirror, and d is the distance between the primary and secondary mirrors.

[0010] In the aforementioned unobstructed dual-mirror antenna with a real exit pupil, the surface shape factor of the primary mirror is 1.

[0011] In the aforementioned unobstructed dual-mirror antenna with a real exit pupil, the surface shape coefficient of the secondary mirror is 1.

[0012] In the aforementioned unobstructed dual-reflector laser antenna with a real exit pupil, the fast-reflecting mirror is located at the exit pupil of the reflective off-axis dual-reflector optical antenna.

[0013] In the aforementioned unobstructed dual-mirror antenna with a real exit pupil, the primary mirror has a Conic coefficient of -1 and a light-transmitting aperture of 230mm; the secondary mirror has a Conic coefficient of -1 and a light-transmitting aperture of 24mm.

[0014] Compared with the prior art, the present invention has the following advantages: (1) Compared with the traditional coaxial folding antenna, the present invention does not have a central obstruction and has a high energy utilization rate; (2) The present invention has a real exit pupil, which can effectively reduce the size of the fast-reflecting mirror and the subsequent relay mirror, and can have a clear optical interface with the subsequent relay mirror, and can be assembled and adjusted step by step. Attached Figure Description

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is the optical path diagram of an unobstructed dual-reflection laser antenna with a real exit pupil provided in an embodiment of the present invention. Detailed Implementation

[0016] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is the optical path diagram of an unobstructed dual-reflector laser antenna with a real exit pupil provided in an embodiment of the present invention. For example... Figure 1 As shown, the unobstructed dual-reflector laser antenna with a real exit pupil includes: a protective window 1, a reflective off-axis dual-reflector optical antenna 2, and a fast-reflecting mirror 3; wherein, parallel light passes through the protective window 1 to reach the reflective off-axis dual-reflector optical antenna 2, and after passing through the reflective off-axis dual-reflector optical antenna 2, small-aperture parallel light is obtained, and the small-aperture parallel light is reflected out by the fast-reflecting mirror 3.

[0018] The protective window 1 is a flat glass plate.

[0019] The off-axis reflective optical antenna 2 employs an off-axis reflective optical configuration. The off-axis reflective optical antenna 2 includes a primary mirror and a secondary mirror; both the primary mirror and the secondary mirror are parabolic surfaces; the focal point of the primary mirror coincides with the focal point of the secondary mirror.

[0020] The relationship between the vertex radius of curvature of the primary mirror and the vertex radius of curvature of the secondary mirror is obtained by the following formula: ; Where R1 is the vertex radius of curvature of the primary mirror, R2 is the vertex radius of curvature of the secondary mirror, and α is the compression ratio of the laser antenna.

[0021] The distance between the primary mirror and the secondary mirror is obtained by the following formula: ; Where R1 is the vertex curvature radius of the primary mirror, R2 is the vertex curvature radius of the secondary mirror, and d is the distance between the primary and secondary mirrors.

[0022] The primary mirror has a Conic coefficient of -1 and a light-transmitting aperture of 230mm; the secondary mirror has a Conic coefficient of -1 and a light-transmitting aperture of 24mm.

[0023] like Figure 1As shown, the unobstructed dual-reflector laser antenna with a real exit pupil in this embodiment includes a protective window 1, a reflective off-axis dual-reflector optical antenna 2, and a fast reflector 3, which are arranged sequentially along the optical axis. The fast reflector 3 is placed at a 45° angle to the optical axis.

[0024] The off-axis reflective optical antenna 2 adopts an off-axis reflective optical configuration, wherein both the primary and secondary mirrors are parabolic surfaces, and their focal points coincide to form an afocal system. The optical antenna has a real exit pupil. The vertex radius of curvature of the primary mirror, the vertex radii of curvature of the primary and secondary mirrors, and the distance between the primary and secondary mirrors are obtained by the following formulas: ; ; Where R1 is the vertex radius of curvature of the primary mirror, R2 is the vertex radius of curvature of the secondary mirror, d is the distance between the primary and secondary mirrors, and α is the compression ratio of the laser antenna.

[0025] The surface shape factor of the primary mirror is: =1; where, The surface shape coefficient of the primary mirror.

[0026] The surface shape coefficient of the secondary mirror is: =1; where, denoted as the surface shape coefficient of the secondary mirror.

[0027] By selecting a suitable relative aperture of the primary mirror and substituting it into the above formula, the initial parameters of the optical system can be quickly obtained. These parameters can then be input into the optical design software, and through off-axis aperture optimization, an optical system that meets the requirements can be obtained.

[0028] The primary mirror has a vertex radius of curvature of 392.03 mm, a Conic coefficient of -1, a distance of 176.41 mm between the primary and secondary mirrors, and a light-transmitting aperture of 230 mm. The secondary mirror has a vertex radius of curvature of 39.20 mm, a Conic coefficient of -1, a distance of 264.62 mm between the secondary and exit pupils, and a light-transmitting aperture of 24 mm.

[0029] The fast reflector 3 is located at the exit pupil of the reflective off-axis optical antenna 2, which can effectively reduce the size of the fast reflector and subsequent relay mirror. Furthermore, the fast reflector 3 can perform high-frequency scanning to cover the field of view of the reflective off-axis optical antenna.

[0030] This embodiment adopts a total internal reflection optical configuration with no central obstruction, which has the advantages of high link establishment efficiency, high reliability, and convenient assembly and adjustment.

[0031] Compared with traditional coaxial folding antennas, this embodiment has no central obstruction and high energy utilization. This embodiment has a real exit pupil, which can effectively reduce the size of the fast reflector and subsequent repeater, and the optical interface with the subsequent repeater is clear, allowing for step-by-step individual assembly and adjustment.

[0032] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A dual-reflection laser antenna with an unobstructed real exit pupil, characterized in that... include: Protective window (1), reflective off-axis dual-lens optical antenna (2), and fast-reflecting mirror (3); among which, Parallel light passes through the protective window (1) and reaches the reflective off-axis dual-lens optical antenna (2). After passing through the reflective off-axis dual-lens optical antenna (2), small-aperture parallel light is obtained. The small-aperture parallel light is reflected by the fast-reflecting mirror (3).

2. The unobstructed dual-reflector laser antenna with a real exit pupil according to claim 1, characterized in that: The protective window (1) is a flat glass plate.

3. The unobstructed dual-reflector laser antenna with a real exit pupil according to claim 1, characterized in that: The off-axis reflective optical antenna (2) adopts an off-axis reflective optical configuration.

4. The unobstructed dual-reflector laser antenna with a real exit pupil according to claim 1, characterized in that: The reflective off-axis dual-mirror optical antenna (2) includes a primary mirror and a secondary mirror; wherein, Both the primary mirror and the secondary mirror are parabolic surfaces; The focal point of the primary mirror coincides with the focal point of the secondary mirror.

5. The unobstructed dual-reflector laser antenna with a real exit pupil according to claim 4, characterized in that: The relationship between the vertex radius of curvature of the primary mirror and the vertex radius of curvature of the secondary mirror is obtained by the following formula: ； Where R1 is the vertex radius of curvature of the primary mirror, R2 is the vertex radius of curvature of the secondary mirror, and α is the compression ratio of the laser antenna.

6. The unobstructed dual-reflector laser antenna with a real exit pupil according to claim 4, characterized in that: The distance between the primary mirror and the secondary mirror is obtained by the following formula: ； Where R1 is the vertex curvature radius of the primary mirror, R2 is the vertex curvature radius of the secondary mirror, and d is the distance between the primary and secondary mirrors.

7. The unobstructed dual-reflector laser antenna with a real exit pupil according to claim 4, characterized in that: The surface shape coefficient of the primary mirror is 1.

8. The unobstructed dual-reflector laser antenna with a real exit pupil according to claim 4, characterized in that: The surface shape coefficient of the secondary mirror is 1.

9. The unobstructed dual-reflector laser antenna with a real exit pupil according to claim 1, characterized in that: The fast-reflecting mirror (3) is located at the exit pupil of the reflective off-axis dual-reflection optical antenna (2).

10. The unobstructed dual-reflector laser antenna with a real exit pupil according to claim 1, characterized in that: The primary mirror has a Conic coefficient of -1 and a light-transmitting aperture of 230mm; the secondary mirror has a Conic coefficient of -1 and a light-transmitting aperture of 24mm.

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