Transmission-type laser emission and detection common-aperture optical system

Abstract

The utility model relates to a transmission-type laser emission and detection common-aperture optical system, and belongs to the technical field of laser systems. Comprising an imaging detection light path and a laser emission light path which share a lens group; the imaging detection light path is composed of a focusing transmitting mirror group, a fast reflecting mirror, a spectroscope and a fine television mirror group; wherein the focusing transmitting lens group comprises a primary lens, a first secondary lens and a second secondary lens, the primary lens has positive focal power, the object side surface of the primary lens is a convex surface, and the image side surface of the primary lens is a plane; the object side surface of the first secondary mirror is a convex surface, and the image side surface of the first secondary mirror is a concave surface; the object side surface of the second secondary mirror is a concave surface, and the image side surface of the second secondary mirror is a convex surface; the fine television lens group comprises a first imaging lens, a second imaging lens, a third imaging lens, a reflector, a fourth imaging lens, an imaging cemented lens and a fifth imaging lens; the imaging detection light path and the laser emission light path share the same aperture through the spectroscope. The imaging view field is improved, the design difficulty is reduced, and the manufacturing cost is high.

Description

Technical Field

[0001] The utility model belongs to the technical field of axial flow fan production and manufacturing, and particularly relates to a transmissive laser emission and detection common-aperture optical system. Background Art

[0002] The main working mode of the laser direct transmission system is based on the common-aperture optical path of laser emission and detection. First, the detection optical path accurately locates the target, and then the laser is focused on the target. To achieve this mode, the traditional design of the common-aperture optical path for laser emission and detection often uses an off-axis reflective beam expander system in combination with a fine tracking optical path, and the laser emission and detection optical paths are confocal in the entire working range by adjusting the focus of the off-axis secondary mirror. However, the off-axis reflective system destroys the rotational symmetry of the system, introduces various non-rotationally symmetric aberrations, and affects the final imaging field of view and imaging quality of the detection system. Moreover, the off-axis reflective system is sensitive to temperature, requires the use of low-thermal expansion structural materials for assembly, and the cost of structural components and lenses is high, which is not conducive to application in small systems.

[0003] The patent with the publication number CN115373122A discloses an optical system and design method for common-aperture laser emission and imaging. The system consists of a front beam expander telescopic group, a dichroic mirror, and a rear imaging group. The beam expander telescopic group is an off-axis two-reflection afocal Cassegrain system, where the primary mirror and the secondary mirror are both parabolic surfaces, the foci of the two mirrors coincide and there is no intermediate image point; the imaging system is an off-axis three-reflection imaging system with folded optical paths, where the primary mirror, the secondary mirror, and the tertiary mirror are all free-form surfaces, and a plane mirror is inserted at the intermediate image point behind the secondary mirror to fold the optical path; the system adopts a total reflection design form, is not sensitive to chromatic aberration, can meet the beam expansion and wide-band imaging requirements of lasers with different wavelengths, and has quite good versatility. Both the beam expander system and the imaging system adopt a volume-compressed structure, the imaging system adopts a free-form surface type, and the common-aperture design, combined with the advantage of the light weight of the reflective system, makes the final system have a small volume, a large field of view, and good image quality, and can be used for small mobile platforms.

[0004] In the process of using the optical systems in the prior art, there are at least the following problems:

[0005] The imaging field of view is not large enough, and the optical path system has high requirements for the installation environment, thus increasing the design difficulty. Content of the Utility Model

[0006] The utility model provides a transmissive laser emission and detection common-aperture optical system, which can greatly improve the imaging field of view, and the optical path system has high requirements for the installation environment, thus increasing the design difficulty.

[0007] To achieve the above object, the utility model is realized through the following technical solutions:

[0008] A transmissive laser emission and detection co-aperture optical system, comprising an imaging detection optical path and a laser emission optical path with a shared mirror group; the imaging detection optical path consists of a focusing emission mirror group, a fast steering mirror, a beam splitter, and a precision TV lens group; wherein the focusing emission mirror group includes, in sequence from the object side to the image side: a primary mirror, a first secondary mirror, and a second secondary mirror: the primary mirror with positive optical power has a convex object side and a flat image side; the first secondary mirror with negative optical power has a convex object side and a concave image side; the second secondary mirror with negative optical power has a concave object side and a convex image side; the precision TV lens group includes, in sequence from the object side to the image side: a first imaging lens, a second imaging lens, a third imaging lens, a reflector, a fourth imaging lens, an imaging cemented lens, and a fifth imaging lens; the beam splitter is used to achieve the co-aperture of the imaging detection optical path and the laser emission optical path.

[0009] Further, the first imaging lens with positive optical power has a convex object side and a concave image side; the second imaging lens with positive optical power has a convex object side and a concave image side; the third imaging lens with negative optical power has a concave object side and a concave image side; the fourth imaging lens with positive optical power has a convex object side and a convex image side; the imaging cemented lens with negative optical power has a concave object side and a convex image side; the fifth imaging lens with positive optical power has a convex object side and a concave image side.

[0010] Further, the focusing emission mirror group is of the Galilean type, composed of a spherical first secondary mirror and a second secondary mirror and an aspherical primary mirror, without an internal focus.

[0011] Further, when acting as an imaging optical system, a distant observed object passes through the focusing emission mirror group, is transmitted through the primary mirror, the first secondary mirror, and the second secondary mirror, and then enters the precision TV lens group through the fast steering mirror and the beam splitter.

[0012] Further, when acting as a laser emission system, the laser is reflected by the beam splitter and the fast steering mirror in sequence and then enters the focusing emission mirror group and is transmitted through: the second secondary mirror, the first secondary mirror, and the primary mirror in sequence and then emitted.

[0013] Further, the half field of view angle of the optical system is less than or equal to 0.21°.

[0014] Further, the working wavelength of the laser emission link is 1065 nm - 1070 nm.

[0015] Further, the working wavelength of the imaging detection link is 798 nm - 818 nm.

[0016] The present utility model provides a transmissive laser emission and detection co-aperture optical system, which jointly constitutes a laser emission optical system and a detection optical system through a focusing emission lens group, a fast steering mirror, a beam splitter, and a precision TV lens group. The co-aperture of the optical path is realized through the beam splitter, and by optimizing the specific lens arrangement structures in the focusing emission lens group and the precision TV lens group, the manufacturing cost and design difficulty of the optical path system are further reduced. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model;

[0019] Figure 2 It is a transfer modulation function diagram of a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model at 200 m;

[0020] Figure 3 It is a transfer modulation function diagram of a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model at 300 m;

[0021] Figure 4 It is a transfer modulation function diagram of a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model at 500 m;

[0022] Figure 5 It is a transfer modulation function diagram of a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model at 1000 m;

[0023] Figure 6 It is a transfer modulation function diagram of a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model at 1500 m;

[0024] Figure 7 It is the encircled energy coefficient of the front telescope group of a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model at 30 m;

[0025] Figure 8 It is the encircled energy coefficient diagram of the front telescope group of a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model at 100 m;

[0026] Figure 9 The encircled energy coefficient diagram of the front telescope group of a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model at 500 m;

[0027] Figure 10 The encircled energy coefficient diagram of the front telescope group of a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model at 1000 m;

[0028] Figure 11 The RMSVS wavelength diagram of the front telescope in a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model;

[0029] Figure 12 The RMSVS field of view diagram of the front telescope in a transmissive laser emission and detection co-aperture optical system provided by an embodiment of the present utility model.

[0030] In the figure:

[0031] 10 - Focusing emission mirror group; 20 - Fast steering mirror; 30 - Beam splitter; 40 - Precision TV mirror group; 101 - Primary mirror; 102 - First secondary mirror; 103 - Second secondary mirror; 401 - First imaging lens; 402 - Second imaging lens; 403 - Third imaging lens; 404 - Reflecting mirror; 405 - Fourth imaging lens; 406 - Imaging cemented lens; 407 - Fifth imaging lens. Specific embodiments

[0032] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0033] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0034] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "plurality" is two or more.

[0035] In the description of this application, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "linkage" should be understood in a broad sense. For example, it can be welding, bolt connection, or riveting; it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0036] Embodiment:

[0037] Please refer to Figure 1 As shown, this embodiment provides a transmissive laser emission and detection co-aperture optical system, including an imaging detection optical path and a laser emission optical path with a shared mirror group; the imaging detection optical path is composed of a focusing emission mirror group 10, a fast steering mirror 20, a beam splitter 30, and a precision TV mirror group 40; among them, the focusing emission mirror group 10 includes, in sequence from the object side to the image side: a main mirror 101, a first secondary mirror 102, and a second secondary mirror 103: the main mirror 101 with a positive optical power, whose object side is convex and image side is flat; the first secondary mirror 102 with a negative optical power, whose object side is convex and image side is concave; the second secondary mirror 103 with a negative optical power, whose object side is concave and image side is convex; the precision TV mirror group 40 includes, in sequence from the object side to the image side: a first imaging lens 401, a second imaging lens 402, a third imaging lens 403, a reflector 404, a fourth imaging lens 405, an imaging doublet 406, and a fifth imaging lens 407; the beam splitter 30 is used to achieve the co-aperture of the imaging detection optical path and the laser emission optical path.

[0038] In this embodiment, the focusing emission mirror group 10 is transmissive. In the precision TV, light passes through the imaging lens, imaging lens, imaging lens, reflector 404, imaging lens, imaging doublet, and imaging lens in sequence and forms an image on the precision TV detector. The imaging detection optical path is responsible for receiving the target optical signal. The optical signal enters the optical path from the focusing emission mirror group 10, is reflected at the fast steering mirror 20, passes through the beam splitter 30, and the precision TV mirror group 40 converges the optical signal onto the detector focal plane; the laser emission optical path is responsible for laser focusing emission. The laser is reflected by the beam splitter 30 and enters the optical path, is reflected at the fast steering mirror 20, and is emitted by the focusing emission mirror group 10; among them, the focusing emission mirror group 10, the fast steering mirror 20, and the beam splitter 30 are all shared for transmission and reception. The focusing emission mirror group 10 focuses to take into account both laser emission and imaging detection. The optical system has a compact volume, a large field of view, and good image quality, and can be applied to a small laser direct transmission system.

[0039] Furthermore, in some implementation manners of this embodiment, such as Figure 1As shown, the first imaging lens 401 with positive optical power has a convex object side and a concave image side; the second imaging lens 402 with positive optical power has a convex object side and a concave image side; the third imaging lens 403 with negative optical power has a concave object side and a concave image side; the fourth imaging lens 405 with positive optical power has a convex object side and a convex image side; the imaging cemented lens 406 with negative optical power has a concave object side and a convex image side; the fifth imaging lens 407 with positive optical power has a convex object side and a concave image side.

[0040] Furthermore, in some embodiments of this embodiment, as Figure 1 shown, the focusing emission lens group 10 is of the Galilean type and is composed of the first spherical mirror 102, the second spherical mirror 103, and the aspherical main mirror 101, and there is no internal focus.

[0041] In this embodiment, the relevant parameters of each lens of the optical lens are shown in Table 1-1:

[0042] Table 1-1 Lens surface type parameters

[0043]

[0044]

[0045] Furthermore, in some embodiments of this embodiment, as Figures 1 to 12 shown, when used as an imaging optical system, the distant object to be observed passes through the focusing emission lens group 10, the main mirror 101, the first mirror 102, and the second mirror 103, and then enters the fine TV lens group 40 through the fast steering mirror 20 and the beam splitter 30.

[0046] In this embodiment, the effective focal length of the imaging detection link is 600 mm. From Figures 2 to 12 the data in, it shows that the imaging effect of the improved optical system is good, and the optical quality is close to the diffraction limit.

[0047] Furthermore, in some embodiments of this embodiment, as Figure 1 shown, when used as a laser emission system, the laser passes through the beam splitter 30 and the fast steering mirror 20 in sequence and then enters the focusing emission lens group 10 and passes through: the second mirror 103, the first mirror 102, and the main mirror 101 in sequence and then is emitted.

[0048] In this embodiment, as Figures 2 to 12 shown, the beam expansion ratio of the laser emission link is 4.9, the improved optical quality is close to the diffraction limit, and the quality of the optical path is improved.

[0049] Furthermore, in some embodiments of this embodiment, as Figure 1As shown, the half field of view angle of the optical system is less than or equal to 0.21°.

[0050] Furthermore, in some embodiments of this embodiment, as Figure 1 shown, the operating wavelength of the laser emission link is 1065 nm - 1070 nm.

[0051] Specifically, at this operating wavelength, a graph of the encircled energy coefficient at different distances as Figures 7 to 10 shown is obtained.

[0052] Furthermore, in some embodiments of this embodiment, as Figure 1 shown, the operating wavelength of the imaging detection link is 798 nm - 818 nm.

[0053] Specifically, at this operating wavelength, a graph of the transfer modulation function at different distances as Figures 2 to 6 shown is obtained.

[0054] In summary, when using a transmissive laser emission and detection common aperture optical path, by separately assembling the optical lens groups at both ends, namely the focusing emission mirror group 10 and the fine TV mirror group 40, and then refracting the optical path through the fast steering mirror 20 and the beam splitter 30, the influence of the environment on the optical path is reduced, thereby improving the stability and imaging quality of the optical path system.

[0055] The above is only the specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope recorded in the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A transmission type laser emission and detection common aperture optical system, comprising: An imaging detection optical path and a laser emission optical path having a common lens group, characterized in that: The imaging detection optical path and the laser emission optical path are both composed of a focusing emission mirror group (10), a fast reflection mirror (20), a beam splitter (30), and a precision video mirror group (40); The focusing transmitting mirror group (10) comprises, in order from the object side to the image side: a main mirror (101), a first secondary mirror (102), and a second secondary mirror (103): The primary mirror (101) has a positive optical power, the object side surface of which is a convex surface, and the image side surface of which is a flat surface; The first submirror (102) has a negative optical power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; The secondary mirror (103) has a negative optical power, the object side surface of which is concave, and the image side surface of which is convex; The precision telephoto lens group (40) includes, in order from the object side to the image side: a first imaging lens (401), a second imaging lens (402), a third imaging lens (403), a reflector (404), a fourth imaging lens (405), an imaging cemented lens (406), and a fifth imaging lens (407); The common aperture of the imaging detection light path and the laser emission light path is achieved through the beam splitter (30).

2. A transmission type laser emission and detection common aperture optical system according to claim 1, characterized in that: The first imaging lens (401) has positive refractive power, and its object side surface is convex and its image side surface is concave; The second imaging lens (402) has positive refractive power, and its object side surface is convex and its image side surface is concave; The third imaging lens (403) has a negative optical power, and its object side surface is concave, and its image side surface is concave; The fourth imaging lens (405) has positive refractive power, and its object side surface is convex, and its image side surface is convex; The imaging cemented lens (406) has a negative optical power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; The fifth imaging lens (407) has positive optical power, and its object side surface is convex and its image side surface is concave.

3. A transmission type laser emission and detection common aperture optical system according to claim 2, characterized in that: The focusing emitting mirror group (10) is of Galilean type, and is composed of the spherical first mirror (102) and the second mirror (103) and the aspherical primary mirror (101), and has no focus inside.

4. A transmission type laser emission and detection common aperture optical system according to claim 3, characterized in that: When used as an imaging optical system, a distant object to be observed is transmitted from the focusing transmitting lens group (10) through the main mirror (101), the first primary mirror (102), and the second secondary mirror (103), and then passes through the fast reflection mirror (20) and the beam splitter (30) into the precision video lens group (40).

5. A transmission type laser emission and detection common aperture optical system according to claim 4, characterized in that: When used as a laser emission system, the laser is reflected by the beam splitter (30) and the quick reflection mirror (20) in sequence, then enters the focusing emission mirror group (10), and passes through the secondary mirror (103), the primary mirror (102), and the primary mirror (101) in sequence, and then is emitted.

6. A transmission type laser emission and detection common aperture optical system according to claim 5, characterized in that: The half field angle of the optical system is less than or equal to 0.21°.

7. A transmission type laser emission and detection common aperture optical system according to claim 6, characterized in that: The operating wavelength of the laser transmission link is 1065nm-1070nm.

8. A transmission type laser emission and detection common aperture optical system according to claim 7, characterized in that: The imaging detection link operates at a wavelength of 798nm-818nm.

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