Adjusting device for double off-axis aspheric beam expanding system

Abstract

The invention discloses an adjusting device for a double off-axis aspheric beam expanding system, which comprises a reflecting mirror two-dimensional adjusting frame, a primary mirror three-dimensional adjusting frame and a secondary mirror four-dimensional adjusting frame, and is characterized in that the reflecting mirror two-dimensional adjusting frame is used for adjusting the pitching and inclination of a reflecting mirror, the primary mirror three-dimensional adjusting frame is used for adjusting the pitching, inclination and rotation of a primary mirror, and the secondary mirror four-dimensional adjusting frame is used for adjusting the pitching, inclination and rotation of a secondary mirror; the secondary mirror four-dimensional adjusting frame is used for adjusting pitching, inclination, rotation and translation of the secondary mirror; parallel light emitted by the laser is reflected by the reflecting mirror, adjustment of off-axis, out-of-focus and generatrix is carried out through the primary mirror three-dimensional adjusting frame and the secondary mirror four-dimensional adjusting frame, beam expansion and collimation of light emitted by the system are achieved, and light beams obtained after beam expansion and collimation enter the optical machine system. The device has the advantages of being simple in structure, small in size, low in cost, high in stability, convenient to mount and dismount, easy to use and high in applicability.

Description

Technical Field

[0001] The invention relates to the field of optical technology, in particular to an adjustment device for a double off-axis aspheric beam expansion system. Background Art

[0002] With the development of optical technology, optical systems have been widely used in material testing, high-altitude exploration, and especially in the military field. However, what kind of optical system structure should be selected to meet the system's design requirements of large aperture, long focal length, high precision, small size, and light weight has become a hot research issue today. The dual off-axis beam expansion system can adjust the spatial position and spatial posture of the optical module installed on it, so as to correct the errors caused by processing and assembly, thereby meeting the requirements of the optical-mechanical system.

[0003] At present, commonly used optical adjustment systems can generally only adjust the position or posture of optical modules. However, for some complex situations, multiple optical adjustment structures are often required to coordinate and adjust, which makes the entire optical-mechanical system bulky and inconvenient to use. Summary of the invention

[0004] The object of the present invention is to provide an adjustment device for a dual off-axis aspheric beam expansion system which has a simple structure, a small volume, a low cost, is convenient to install and disassemble, and is easy to use.

[0005] The technical solution to achieve the purpose of the present invention is: an adjustment device for a dual off-axis aspheric beam expansion system, comprising a two-dimensional adjustment frame for a reflector, a three-dimensional adjustment frame for a primary mirror, and a four-dimensional adjustment frame for a secondary mirror;

[0006] The two-dimensional adjustment frame of the reflector is used to adjust the pitch and tilt of the reflector;

[0007] The primary mirror three-dimensional adjustment frame is used to adjust the pitch, tilt and rotation of the primary mirror;

[0008] The secondary mirror four-dimensional adjustment frame is used to adjust the pitch, tilt, rotation and translation of the secondary mirror;

[0009] The parallel light emitted by the laser is deflected by the reflector and adjusted in three categories: off-axis, defocus, and busbar using the three-dimensional adjustment frame of the primary mirror and the four-dimensional adjustment frame of the secondary mirror, to achieve beam expansion and collimation of the system's output light. The expanded and collimated light beam is incident on the optical-mechanical system.

[0010] Furthermore, the reflector two-dimensional adjustment frame includes a reflector, a reflector frame and a reflector frame;

[0011] The reflector is installed on the reflector frame; four threaded holes are arranged at the four corners of the reflector frame, and mounting holes corresponding to the positions of the threaded holes are arranged at the top of the reflector frame, and the reflector frame and the reflector frame are connected by screws; an elastic washer is arranged between the reflector frame and the reflector frame for isolation, and the elastic washer is squeezed by adjusting the screws connecting the square frame and the frame to realize the x and y two-dimensional adjustment of the elliptical reflector; the upper half and the lower half of the reflector frame are bent at a fixed angle, and the bottom of the reflector frame is provided with a mounting hole for fixedly installing the reflector frame.

[0012] Furthermore, the reflector is used to realize the deflection of the light beam, and a visible light interferometer is used to emit parallel light. A spot positioning plate consistent with the center height of the system is placed in the light path after being deflected by the reflector. The screws connecting the square mirror frame and the mirror frame are adjusted to squeeze the elastic gasket to realize the x and y two-dimensional adjustment of the elliptical reflector, so that the output light spot is located at the center of the spot positioning plate, thereby completing the position adjustment of the two-dimensional adjustment frame of the reflector.

[0013] Furthermore, the main mirror three-dimensional adjustment frame includes a main mirror, a main mirror frame, a main mirror movable turntable, a main mirror semicircular pressure plate, a main mirror nylon ring, a main mirror bearing, and a main mirror seat;

[0014] The main mirror frame is provided with circular gluing holes around it for gluing the main mirror lens to the main mirror frame; screw holes are evenly distributed around the edge of the main mirror movable turntable, the main mirror frame and the main mirror movable turntable are connected by screws, separated by an elastic gasket in the middle, and the elastic gasket is squeezed by the fine-tuning screw to adjust the inclination of the optical axis in the x and y directions; the main mirror semicircular pressure plate installs the main mirror bearing on the main mirror seat; the main mirror movable turntable is provided with a dial hole, and the dial hole of the main mirror movable turntable is turned to adjust the rotation dimension of the generatrix, and it is fixed with a top screw after the adjustment is completed; the bottom of the main mirror seat is provided with a mounting hole for fixing the main mirror seat.

[0015] Furthermore, the primary mirror is used to achieve beam expansion, and a visible light interferometer is used to measure the mirror shape of the primary mirror. The plane reflector is placed opposite to the primary mirror. After the visible light interferometer is equipped with a spherical lens, the outgoing laser converges at the focus of the measured primary mirror, and a small aperture diaphragm is placed at the focus of the primary mirror. A beam of parallel light is formed after reflection by the primary mirror, and then reflected back to the primary mirror by a standard plane reflector and finally returns to the interferometer to form interference. The wavefront information is calculated through interference fringes, and the spatial postures of the standard plane mirror and the primary mirror are adjusted according to the wavefront information. For the adjustment of the primary mirror, the elastic gasket is squeezed by fine-tuning the screws connecting the primary mirror frame and the primary mirror movable turntable to achieve the adjustment of the inclination of the optical axis in the x and y directions. The rotation of the primary mirror is achieved by turning the primary mirror movable turntable until the measured mirror surface accuracy is better than the measurement accuracy, and the position adjustment of the primary mirror three-dimensional adjustment frame is completed.

[0016] Furthermore, the secondary mirror four-dimensional adjustment frame includes a secondary mirror, a secondary mirror frame, a secondary mirror movable turntable, a secondary mirror semicircular pressure plate, a secondary mirror nylon ring, a secondary mirror bearing, and a secondary mirror seat;

[0017] The secondary mirror frame is provided with circular gluing holes around it for gluing the secondary mirror lens to the secondary mirror frame; screw holes are evenly distributed around the edge of the secondary mirror movable turntable, the secondary mirror frame and the secondary mirror movable turntable are connected by screws, separated by an elastic gasket in the middle, and the elastic gasket is squeezed by the fine-tuning screw to achieve the adjustment of the inclination of the optical axis in the x and y directions; the secondary mirror semicircular pressure plate installs the secondary mirror bearing on the secondary mirror seat; the secondary mirror movable turntable is provided with a dial hole, and the dial hole of the secondary mirror movable turntable is dialed to adjust the rotation dimension of the generatrix, and it is fixed with a top screw after the adjustment is completed; a sliding guide rail is provided at the bottom of the secondary mirror seat, and the secondary mirror seat is installed by the sliding guide rail, and the secondary mirror seat can move horizontally on the sliding guide rail.

[0018] Furthermore, the secondary mirror is used to realize the adjustment of three categories of off-axis, defocusing and main line of the light beam; the rotation of the main section of the secondary mirror only affects the emission or incident direction of the system parallel light, and can be adjusted according to the actual parallel light direction and the center height; a crosshair is placed at the exit port of the visible light interferometer, and the center height of the crosshair is the same as the center height of the system. The same graticule is placed at the exit port after beam expansion through coordinate transformation. When the main mirror is well adjusted, the elastic gasket is squeezed by the fine-tuning screw to realize the adjustment of the inclination of the optical axis in the x and y directions; the rotation of the main mirror and the translation of the secondary mirror seat on the sliding guide rail are realized by turning the secondary mirror movable turntable so that the crosshairs of the two coincide, that is, the main section of the system is adjusted in place.

[0019] Compared with the prior art, the significant advantages of the present invention are: (1) only three components are needed to reasonably distribute the three types of adjustment requirements of off-axis, defocus and busbar to two aspheric mirror frames, reducing space waste, meeting the needs of miniaturization of optical products, and reducing costs; (2) The optical path is easy to adjust, and the alignment of the beam expansion system can be ensured by fine-tuning the nut and rotating the movable plate. The structure of each component is simple, easy to install and disassemble, easy to use, and highly applicable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of an adjustment device for a dual off-axis aspheric beam expansion system of the present invention.

[0021] Figure 2 It is a schematic structural diagram of the two-dimensional adjustment frame of the reflector in the present invention.

[0022] Figure 3 It is a structural schematic diagram of the three-dimensional adjustment frame of the primary mirror in the present invention.

[0023] Figure 4 It is a structural schematic diagram of the secondary mirror four-dimensional adjustment frame in the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0025] like Figure 1 As shown, the present invention provides an adjustment device for a dual off-axis aspheric beam expansion system, comprising a two-dimensional adjustment frame 2 for a reflector, a three-dimensional adjustment frame 3 for a primary mirror, and a four-dimensional adjustment frame 4 for a secondary mirror;

[0026] The two-dimensional adjustment frame 2 of the reflector is used to adjust the pitch and tilt of the reflector;

[0027] The primary mirror three-dimensional adjustment frame 3 is used to adjust the pitch, tilt and rotation of the primary mirror;

[0028] The secondary mirror four-dimensional adjustment frame 4 is used to adjust the pitch, tilt, rotation and translation of the secondary mirror;

[0029] The parallel light emitted by the laser 1 is deflected by the reflector 2, and the three-dimensional adjustment frame 3 of the primary mirror and the four-dimensional adjustment frame 4 of the secondary mirror are used to perform three types of adjustments, namely, off-axis, defocusing, and main line, to achieve beam expansion and collimation of the system's output light. The expanded and collimated light beam is incident on the optical-mechanical system 5.

[0030] As a specific example, the two-dimensional reflector adjustment frame 2 includes a reflector 2-1, a reflector frame 2-2 and a reflector frame 2-3. Figure 2 As shown;

[0031] The reflector 2-1 is installed on the reflector frame 2-2; four threaded holes are set at the four corners of the reflector frame 2-2, and a mounting hole corresponding to the position of the threaded hole is set at the top of the reflector frame 2-3, and the reflector frame 2-2 and the reflector frame 2-3 are connected by screws; an elastic gasket is set between the reflector frame 2-2 and the reflector frame 2-3 for isolation, and the elastic gasket is squeezed by adjusting the screws connecting the square frame 2-2 and the frame 2-3 to achieve x, y two-dimensional adjustment of the elliptical reflector; the upper half and the lower half of the reflector frame 2-3 are bent at a fixed angle, and the bottom of the reflector frame 2-3 is provided with a mounting hole for fixedly installing the reflector frame 2-3.

[0032] As a specific example, the reflector 2-1 is used to realize the deflection of the light beam, and a visible light interferometer is used to emit parallel light. A spot positioning plate that is consistent with the center height of the system is placed in the light path after being deflected by the reflector 2-1. The screws connecting the square mirror frame 2-2 and the mirror frame 2-3 are adjusted to squeeze the elastic gasket to realize the x and y two-dimensional adjustment of the elliptical reflector, so that the output light spot is located at the center of the spot positioning plate, thereby completing the position adjustment of the reflector two-dimensional adjustment frame 2.

[0033] As a specific example, the main mirror three-dimensional adjustment frame 3 includes a main mirror 3-1, a main mirror frame 3-2, a main mirror movable turntable 3-3, a main mirror semicircular pressure plate 3-4, a main mirror nylon ring 3-5, a main mirror bearing 3-6, and a main mirror seat 3-7. Figure 3 As shown;

[0034] The main mirror frame 3-2 is provided with circular gluing holes around it for gluing the main mirror 3-1 lens to the main mirror frame 3-2; screw holes are evenly distributed around the edge of the main mirror movable turntable 3-3, the main mirror frame 3-2 and the main mirror movable turntable 3-3 are connected by screws, separated by an elastic gasket in the middle, and the elastic gasket is squeezed by the fine-tuning screw to adjust the inclination of the optical axis in the x and y directions; the main mirror semicircular pressure plate 3-4 installs the main mirror bearing 3-5 on the main mirror seat 3-7; the main mirror movable turntable 3-3 is provided with a dial hole, and the dial hole of the main mirror movable turntable 3-3 is turned to adjust the rotation dimension of the generatrix, and it is fixed with a top screw after the adjustment is completed; the bottom of the main mirror seat 3-7 is provided with a mounting hole for fixing the main mirror seat 3-7.

[0035] As a specific example, the main mirror 3-1 is used to achieve beam expansion, and a visible light interferometer is used to measure the mirror shape of the main mirror 3-1. A plane reflector is placed opposite to the main mirror 3-1. After the visible light interferometer is equipped with a spherical lens, its output laser converges at the focus of the measured main mirror 3-1, and a small aperture diaphragm is placed at the focus of the main mirror 3-1. A beam of parallel light is formed by reflection from the main mirror 3-1, and then reflected back to the main mirror 3-1 through a standard plane reflector and finally returns to the interferometer to form interference. The wavefront information is calculated through interference fringes, and the spatial postures of the standard plane mirror and the main mirror 3-1 are adjusted according to the wavefront information; for the adjustment of the main mirror 3-1, the screws connecting the main mirror frame 3-2 and the main mirror movable turntable 3-3 are fine-tuned to squeeze the elastic gasket to achieve the adjustment of the inclination of the optical axis in the x and y directions; the rotation of the main mirror 3-1 is achieved by turning the main mirror movable turntable 3-2 until the measured mirror surface accuracy is better than the measurement accuracy, and the position adjustment of the three-dimensional adjustment frame of the main mirror 3-1 is completed.

[0036] As a specific example, the secondary mirror four-dimensional adjustment frame 4 includes a secondary mirror 4-1, a secondary mirror frame 4-2, a secondary mirror movable turntable 4-3, a secondary mirror semicircular pressure plate 4-4, a secondary mirror nylon ring 4-5, a secondary mirror bearing 4-6, and a secondary mirror seat 4-7. Figure 4 As shown;

[0037] The secondary mirror frame 4-2 is provided with circular gluing holes around it for gluing the secondary mirror 4-1 lens to the secondary mirror frame 4-2; screw holes are evenly distributed around the edge of the secondary mirror movable turntable 4-3, the secondary mirror frame 4-2 and the secondary mirror movable turntable 4-3 are connected by screws, separated by an elastic gasket in the middle, and the elastic gasket is squeezed by the fine-tuning screw to achieve the adjustment of the inclination of the optical axis in the x and y directions; the secondary mirror semicircular pressure plate 4-4 installs the secondary mirror bearing 4-5 on the secondary mirror seat 4-7; the secondary mirror movable turntable 4-3 is provided with a dial hole, and the dial hole of the secondary mirror movable turntable 4-3 is dialed to adjust the rotation dimension of the generatrix, and it is fixed with a top screw after the adjustment is completed; a sliding guide rail is provided at the bottom of the secondary mirror seat 4-7, and the secondary mirror seat 4-7 is installed by the sliding guide rail, and the secondary mirror seat 4-7 can move horizontally on the sliding guide rail.

[0038] As a specific example, the secondary mirror 4-1 is used to realize the adjustment of three categories of light beams: off-axis, defocusing, and main line; the rotation of the main section of the secondary mirror 4-1 only affects the emission or incident direction of the system parallel light, and can be adjusted according to the actual parallel light direction and the center height; a crosshair is placed at the exit port of the visible light interferometer, and the center height of the crosshair is the same as the center height of the system. Through coordinate transformation, the same graticule is placed at the exit port after beam expansion. When the main mirror 3-1 is adjusted well, the elastic gasket is squeezed by the fine-tuning screw to adjust the inclination of the optical axis in the x and y directions; the rotation of the main mirror and the translation of the secondary mirror base 4-6 on the sliding guide rail are realized by turning the secondary mirror movable turntable 4-3 so that the crosshairs of the two coincide, that is, the main section of the system is adjusted in place.

[0039] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An adjustment device for a dual off-axis aspheric beam expansion system, characterized in that: It comprises a two-dimensional adjustment frame for a reflecting mirror (2), a three-dimensional adjustment frame for a primary mirror (3) and a four-dimensional adjustment frame for a secondary mirror (4); The two-dimensional adjustment frame (2) of the reflector is used to adjust the pitch and tilt of the reflector; The primary mirror three-dimensional adjustment frame (3) is used to adjust the pitch, tilt and rotation of the primary mirror; The secondary mirror four-dimensional adjustment frame (4) is used to adjust the pitch, tilt, rotation and translation of the secondary mirror; The parallel light emitted by the laser (1) is deflected by a reflector (2), and is adjusted in three categories, namely, off-axis, defocusing and generatrix, by using a primary mirror three-dimensional adjustment frame (3) and a secondary mirror four-dimensional adjustment frame (4), so as to achieve beam expansion and collimation of the system output light, and the beam after beam expansion and collimation is incident on an optical machine system (5).

2. The adjustment device for a dual off-axis aspheric beam expansion system according to claim 1, characterized in that: The reflector two-dimensional adjustment frame (2) comprises a reflector (2-1), a reflector frame (2-2) and a reflector frame (2-3); The reflector (2-1) is mounted on a reflector frame (2-2); four threaded holes are arranged at four corners of the reflector frame (2-2); a mounting hole corresponding to the position of the threaded hole is arranged at the top of the reflector frame (2-3); the reflector frame (2-2) and the reflector frame (2-3) are connected by screws; an elastic washer is arranged between the reflector frame (2-2) and the reflector frame (2-3) for isolation; the elastic washer is squeezed by adjusting the screws connecting the square frame (2-2) and the frame (2-3) to achieve x and y two-dimensional adjustment of the elliptical reflector; the upper half and the lower half of the reflector frame (2-3) are bent at a fixed angle; the bottom of the reflector frame (2-3) is provided with a mounting hole for fixedly mounting the reflector frame (2-3).

3. The adjustment device for a dual off-axis aspheric beam expansion system according to claim 2, characterized in that: The reflector (2-1) is used to realize the deflection of the light beam. A visible light interferometer is used to emit parallel light. A light spot positioning plate having the same height as the center of the system is placed in the light path after being deflected by the reflector (2-1). The screws connecting the square mirror frame (2-2) and the mirror frame (2-3) are adjusted to squeeze the elastic gasket, thereby realizing the x and y two-dimensional adjustment of the elliptical reflector, so that the emitted light spot is located at the center of the light spot positioning plate, thereby completing the position adjustment of the reflector two-dimensional adjustment frame (2).

4. The adjustment device for a dual off-axis aspheric beam expansion system according to claim 1, characterized in that: The main mirror three-dimensional adjustment frame (3) comprises a main mirror (3-1), a main mirror frame (3-2), a main mirror movable turntable (3-3), a main mirror semicircular pressure plate (3-4), a main mirror nylon ring (3-5), a main mirror bearing (3-6), and a main mirror seat (3-7); The main mirror frame (3-2) is provided with circular gluing holes around it for gluing the lens of the main mirror (3-1) to the main mirror frame (3-2); screw holes are evenly distributed around the edge of the main mirror movable turntable (3-3); the main mirror frame (3-2) and the main mirror movable turntable (3-3) are connected by screws and separated by an elastic washer in the middle; the elastic washer is squeezed by the fine-tuning screw to adjust the inclination of the optical axis in the x and y directions; the main mirror semicircular pressure plate (3-4) installs the main mirror bearing (3-5) on the main mirror seat (3-7); the main mirror movable turntable (3-3) is provided with a dial hole, and the dial hole of the main mirror movable turntable (3-3) is dialed to adjust the rotation dimension of the generatrix, and is fixed with a top screw after the adjustment is completed; the bottom of the main mirror seat (3-7) is provided with a mounting hole for fixing and installing the main mirror seat (3-7).

5. The adjustment device for a dual off-axis aspheric beam expansion system according to claim 4, characterized in that: The primary mirror (3-1) is used to expand the light beam. The mirror shape of the primary mirror (3-1) is measured using a visible light interferometer. A plane reflector and the primary mirror (3-1) are placed opposite to each other. After the visible light interferometer is equipped with a spherical lens, the emitted laser is converged at the focus of the measured primary mirror (3-1). A small aperture diaphragm is placed at the focus of the primary mirror (3-1). A beam of parallel light is formed after being reflected by the primary mirror (3-1). The beam is then reflected back to the primary mirror (3-1) by a standard plane reflector and finally returns to the interferometer to form interference. The wavefront information is calculated based on the fringes, and the spatial postures of the standard plane mirror and the primary mirror (3-1) are adjusted respectively according to the wavefront information; for the adjustment of the primary mirror (3-1), the screws connecting the primary mirror frame (3-2) and the primary mirror movable turntable (3-3) are fine-tuned to squeeze the elastic gasket to adjust the inclination of the optical axis in the x and y directions; the primary mirror (3-1) is rotated by turning the primary mirror movable turntable (3-2) until the measured mirror surface accuracy is better than the measurement accuracy, thereby completing the position adjustment of the three-dimensional adjustment frame of the primary mirror (3-1).

6. The adjustment device for a dual off-axis aspheric beam expansion system according to claim 1, characterized in that: The secondary mirror four-dimensional adjustment frame (4) comprises a secondary mirror (4-1), a secondary mirror frame (4-2), a secondary mirror movable turntable (4-3), a secondary mirror semicircular pressure plate (4-4), a secondary mirror nylon ring (4-5), a secondary mirror bearing (4-6), and a secondary mirror seat (4-7); The secondary mirror frame (4-2) is provided with circular gluing holes around it for gluing the lens of the secondary mirror (4-1) to the secondary mirror frame (4-2); screw holes are evenly distributed around the edge of the secondary mirror movable turntable (4-3); the secondary mirror frame (4-2) and the secondary mirror movable turntable (4-3) are connected by screws and separated by an elastic washer in the middle; the elastic washer is squeezed by the fine-tuning screw to adjust the inclination of the optical axis in the x and y directions; the secondary mirror semicircular pressure plate (4-4) installs the secondary mirror bearing (4-5) on the secondary mirror seat (4-7); the secondary mirror movable turntable (4-3) is provided with a dial hole, and the dial hole of the secondary mirror movable turntable (4-3) is dialed to adjust the rotation dimension of the generatrix, and is fixed by a top screw after the adjustment is completed; a sliding guide rail is provided at the bottom of the secondary mirror seat (4-7), and the secondary mirror seat (4-7) is installed by the sliding guide rail, and the secondary mirror seat (4-7) can move horizontally on the sliding guide rail.

7. The adjustment device for a dual off-axis aspheric beam expansion system according to claim 6, characterized in that: The secondary mirror (4-1) is used to achieve three types of adjustment of the off-axis, defocusing and main line of the light beam; the rotation of the main section of the secondary mirror (4-1) only affects the emission or incident direction of the system parallel light, and can be adjusted according to the actual parallel light direction and the center height; a crosshair is placed at the exit port of the visible light interferometer, and the center height of the crosshair is the same as the center height of the system; the same graticule is placed at the exit port after beam expansion through coordinate transformation; when the main mirror (3-1) is well adjusted, the elastic gasket is squeezed by the fine-tuning screw to achieve the adjustment of the inclination of the optical axis in the x and y directions; the rotation of the main mirror and the translation of the secondary mirror base (4-6) on the sliding guide rail are achieved by toggling the secondary mirror movable turntable (4-3) so that the crosshairs of the two coincide, that is, the main section of the system is adjusted in place.

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