Large-aperture fast polarization modulation device

Abstract

The utility model discloses a kind of large aperture fast polarization modulation devices, including preposed rotating frame, post rotating frame, the preposed rotating frame is provided with several mirror group installation groove, the post rotating frame is provided with several mirror group installation groove;Several mirror group installation groove on the preposed rotating frame are installed with different reducing magnification beam-reducing mirror group, the mirror group installation groove on the post rotating frame are installed with different expansion magnification beam-expanding mirror group;Polarization modulation component is arranged between the beam-reducing mirror group and beam-expanding mirror group, polarization modulation component includes at least one fixed grating and at least one translation grating capable of moving along the periodic direction of fixed grating;The utility model can adapt to the polarization adjustment of flexible magnification combination of large aperture linearly polarized light, finally different aperture, different polarization angle light can be obtained.

Description

Technical Field

[0001] This invention belongs to the technical field of light polarization adjustment, specifically relating to a large-aperture fast polarization modulation device. Background Technology

[0002] Polarization optical modulation has wide applications in scientific research and imaging, and the requirements for polarization modulation rate and the adaptability of modulation equipment are becoming increasingly higher. In patent 'CN116642832A', a fast polarization modulation component using a subwavelength structure is proposed. This method has the advantages of fast polarization modulation rate, but the surface of the subwavelength structure is usually limited by the processing technology, and the local processing accuracy requirements are high, which makes large-aperture processing difficult. In optical path applications, especially in large-aperture optical paths, the adaptability is low.

[0003] To address the aperture limitations of the aforementioned fast polarization modulation components, this invention proposes a large-aperture fast polarization modulation module. It combines a large-aperture traditional refractive optical system with a small-aperture polarization modulation component in a single optical path, and designs a mirror assembly modulation mechanism to achieve flexible magnification combinations and polarization adjustment of large-aperture linearly polarized light, ultimately obtaining light rays with different apertures and polarization angles. The module mainly comprises a front beam-shrinking mirror assembly, a polarization modulation component, and a rear beam-expanding mirror assembly. Utility Model Content

[0004] This invention discloses a large-aperture fast polarization modulation device, which can adapt to large-aperture linearly polarized light and perform flexible polarization adjustment by combining magnification, ultimately obtaining light with different apertures and different polarization angles.

[0005] This utility model is achieved through the following technical solution: A large-aperture fast polarization modulation device includes a front rotating frame and a rear rotating frame. The front rotating frame is provided with a plurality of mirror mounting slots, and the rear rotating frame is provided with a plurality of mirror mounting slots. Beam-shrinking mirrors with different reduction magnifications are installed in the mirror mounting slots on the front rotating frame, and beam-expanding mirrors with different magnifications are installed in the mirror mounting slots on the rear rotating frame. A polarization modulation component is provided between the beam-shrinking mirrors and the beam-expanding mirrors. The polarization modulation component includes at least one fixed grating and at least one translation grating that can move along the periodic direction of the fixed grating.

[0006] A beam-shrinking mirror group, a polarization modulation component, and a beam-expanding mirror group, all located on the same optical axis, constitute an optical path adjustment system. The light first passes through the beam-shrinking mirror group to shrink the optical aperture, ensuring that the optical aperture after beam shrinking is less than or equal to the effective aperture of the polarization modulation component. The light then passes through the polarization modulation component. The fixed grating and the translation grating have the same period. The translation grating can be shifted along the period direction of the fixed grating. After passing through the fixed grating and the translation grating, the left-hand and right-hand circular polarization components of the light acquire different phase delays, causing the polarization direction of the final outgoing light to be modulated by a specific rotation angle. This rotation angle is related to the translation amount of the translation grating. The polarization-modulated light then passes through the beam-expanding mirror group to expand the optical aperture.

[0007] To better realize this utility model, the translation device further includes a high-precision translation motor and a motor controller. The motor controller is connected to the high-precision translation motor, and the translation output shaft of the high-precision translation motor is connected to one side of the translation grating to drive the translation grating to move along the periodic direction.

[0008] To better realize this utility model, the shrinkage magnification of the beam shrinking lens group located at both ends of the optical axis is the same as the magnification magnification of the beam expanding lens group.

[0009] To better realize this utility model, the beam shrinking lens assembly further includes a beam shrinking lens frame, on which a first condensing lens and a first collimating lens are arranged sequentially along the optical axis.

[0010] To better realize this utility model, the beam expander assembly further includes a beam expander frame, on which a second diverging lens and a second collimating lens are arranged sequentially along the optical axis.

[0011] To better realize this utility model, the front rotating frame further includes an indexing rotating device and a rotating frame body. The indexing rotating device is connected to the rotating shaft at the center of the rotating frame body. Several mirror assembly mounting slots are evenly arranged circumferentially around the rotating shaft on the rotating frame body. The structure of the front rotating frame is the same as that of the rear rotating frame.

[0012] To better realize this utility model, the indexing rotation device further includes a rotating motor, a drive disk, and an indexing rotation frame. The rotating shaft at the center of the drive disk is connected to the output shaft of the rotating motor. A drive boss is provided at the edge of the drive disk. The rotating shaft at the center of the indexing rotation frame is coaxially connected to the rotation frame body. Several indexing grooves that slide and cooperate with the drive boss are evenly distributed along the circumference of the indexing rotation frame.

[0013] Compared with the prior art, this utility model has the following advantages and beneficial effects: This invention enables flexible combinations of beam shrinking and beam expanding lens groups with different magnifications by rotating the front and rear rotating frames, allowing for different magnifications of the light beam. Simultaneously, by moving the translation grating in the polarization modulation component relative to the fixed grating along the periodic direction, the polarization angle of the light beam can be flexibly modulated. Ultimately, light beams with different apertures and polarization angles can be obtained according to actual usage requirements. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a large-aperture fast polarization modulation device. Figure 2 This is a schematic diagram of the polarization modulation component. Figure 3 This is a schematic diagram of the front rotating frame; Figure 4 This is a schematic diagram of the rear-mounted rotating frame. Figure 5 This is a schematic diagram of the indexing rotary device; Figure 6 This is a schematic diagram of the mirror assembly being installed on the rotating frame body.

[0015] Wherein: 1-Front rotating frame; 2-Rear rotating frame; 3-Beam shrinking lens group; 4-Beam expanding lens group; 5-Polarization modulation component; 11-Indexing rotating device; 12-Rotating frame body; 111-Rotating motor; 112-Drive disk; 113-Indexing rotating frame; 114-Drive boss; 115-Indexing slot; 31-First condensing lens; 32-First collimating lens; 41-Second diverging lens; 42-Second collimating lens; 51-Fixed grating; 52-Translation grating; 53-Translation device; 531-High-precision translation motor; 532-Motor controller. Detailed Implementation

[0016] Example 1: This embodiment provides a large-aperture fast polarization modulation device, such as... Figures 1-4 As shown, the system includes a front rotating frame 1 and a rear rotating frame 2. The front rotating frame 1 is provided with several mirror assembly mounting slots, and the rear rotating frame 2 is provided with several mirror assembly mounting slots. Beam-shrinking mirror assemblies 3 with different reduction magnifications are installed in the several mirror assembly mounting slots on the front rotating frame 1, and beam-expanding mirror assemblies 4 with different magnifications are installed in the mirror assembly mounting slots on the rear rotating frame 2. A polarization modulation component 5 is provided between the beam-shrinking mirror assemblies 3 and the beam-expanding mirror assemblies 4. The polarization modulation component 5 includes at least one fixed grating 51 and at least one translation grating 52 that can move along the periodic direction of the fixed grating 51.

[0017] like Figure 6As shown, both the front rotating frame 1 and the rear rotating frame 2 have four mirror mounting slots evenly distributed circumferentially. Therefore, four sets of beam-shrinking mirrors 3 with different reduction magnifications can be mounted on the front rotating frame 1, and four sets of beam-expanding mirrors 4 with different magnifications can be mounted on the rear rotating frame 2. The reduction magnification of the beam-shrinking mirrors 3 and the magnification of the beam-expanding mirrors 4 can be flexibly selected according to actual optical path adjustment requirements. Simultaneously, by rotating the front rotating frame 1 and the rear rotating frame 2, different beam-shrinking mirrors 3 and beam-expanding mirrors 4 can be rotated to the optical axis coaxial with the polarization modulation component 5, thereby forming different combinations of beam-shrinking and beam-expanding polarization modulation.

[0018] When the large-aperture linearly polarized light to be modulated is incident on the beam shrinking lens group 3, the aperture of the light before incident is D, and the shrinkage ratio of the beam shrinking lens group 3 is d / D. Then, the aperture of the light after passing through the beam shrinking lens group 3 is reduced to d, and the aperture d of the light is less than or equal to the effective light transmission aperture of the polarization modulation component 5, so as to ensure that the polarization modulation component 5 can fully polarize the light.

[0019] The light beam, after passing through the beam-constricted grating 51, continues through the fixed grating 51. Both the fixed grating 51 and the translation grating 52 have a grating period of k. The translation grating 52 is moved by Δx along the periodic direction. After passing through the fixed grating 51 and the translation grating 52, the left-hand and right-hand circular polarization components of the light beam experience different phase delays, causing the polarization direction of the outgoing light beam to be modulated by a specific rotation angle α. The calculation formula is as follows: α = 2πΔx / k; After polarization modulation, the light finally passes through beam expander group 4, which has a magnification of D / d. This magnification can expand the aperture of the light to D, ensuring that the aperture of the light remains unchanged, but the polarization angle is rotated by a specific angle.

[0020] Example 2: This embodiment is a further optimization based on Embodiment 1, such as... Figure 1 and Figure 2 As shown, a translation device 53 is provided on one side of the translation grating 52. The moving end of the translation device 53 is connected to one side of the translation grating 52 and drives the translation grating 52 to move along the periodic direction. The translation device 53 includes a high-precision translation motor 531 and a motor controller 532. The motor controller 532 is connected to the high-precision translation motor 531. The translation output shaft of the high-precision translation motor 531 is connected to one side of the translation grating 52 to drive the translation grating 52 to move along the periodic direction.

[0021] The high-precision translation motor 531 drives the translation grating 52 to move along the periodic direction, which refers to the direction perpendicular to the grating direction on the fixed grating 51. The motor controller 532 outputs a control signal to the high-precision translation motor 531, which can remotely operate the high-precision translation motor 531 to drive the translation grating 52 to move, thereby realizing the polarization modulation of light.

[0022] Furthermore, the high-precision translation motor 531 includes a high-precision voice coil motor module, which is a combination of a voice coil motor, a linear grating, and a driver. Its model is G-PGTWI6 / 100SEKHDD2 or WDLS2005. The total stroke of the high-precision translation motor 531 is 5mm, the rated thrust is 5N, the positioning repeatability is 3μm, and the resolution is 1μm.

[0023] The other parts of this embodiment are the same as those in Embodiment 1, so they will not be described again.

[0024] Example 3: This embodiment is a further optimization based on the above embodiment 1 or 2. The shrinkage ratio of the beam shrinking lens group 3 located at both ends of the optical axis is the same as the magnification ratio of the beam expanding lens group 4. This ensures that after the light passes through the beam shrinking lens group 3, the polarization modulation component 5, and the beam expanding lens group 4, it can produce light with the same aperture but rotated polarization angle. That is, only the polarization angle of the light is changed, without changing the aperture of the light.

[0025] It should be noted that, depending on the actual light adjustment needs, the beam shrinking lens group 3 and the beam expanding lens group 4 with different magnifications can be flexibly combined to obtain light with different characteristics.

[0026] Furthermore, such as Figure 3 and Figure 4 As shown, the beam shrinking lens group 3 includes a beam shrinking lens frame, on which a first condensing lens 31 and a first collimating lens 32 are arranged sequentially along the optical axis. The beam expanding lens group 4 includes a beam expanding lens frame, on which a second diverging lens 41 and a second collimating lens 42 are arranged sequentially along the optical axis.

[0027] The first condensing lens 31 includes a convex condensing lens, and the second collimating lens 42 includes a concave diverging lens. The first condensing lens 31 converges the light beam to reduce its aperture, the second diverging lens 41 diverges the light beam to increase its aperture, and the second collimating lens 42 collimates the increased aperture light beam. The first collimating lens 32 and the second collimating lens 42 are used to adjust the converged or expanded light beam to parallel light.

[0028] The other parts of this embodiment are the same as those in Embodiment 1 or 2 above, so they will not be described again.

[0029] Example 4: This embodiment is a further optimization based on any one of embodiments 1-3 above, such as... Figure 3 , Figure 5 , Figure 6 As shown, the front rotating frame 1 includes an indexing rotating device 11 and a rotating frame body 12. The indexing rotating device 11 is connected to the rotating shaft at the center of the rotating frame body 12. Several mirror assembly mounting slots are evenly arranged circumferentially around the rotating shaft on the rotating frame body 12. The structure of the front rotating frame 1 is the same as that of the rear rotating frame 2.

[0030] The beam shrinking lens group 3 or beam expanding lens group 4 with different magnifications are installed into the lens group mounting slots and locked with pressure caps and screws to ensure that the beam shrinking lens group 3 and beam expanding lens group 4 are stably fixed on the rotating frame body 12. The indexing rotation device 11 drives the rotating frame body 12 to rotate at a fixed indexing angle each time, thereby enabling rotation and switching between different lens group mounting slots. This allows the beam shrinking lens group 3 or beam expanding lens group 4 with different magnifications to rotate to the optical axis coaxial with the polarization modulation component 5, realizing a flexible combination of different beam shrinking magnifications and beam expanding magnifications.

[0031] Furthermore, the indexing rotation device 11 includes a rotation motor 111, a drive disk 112, and an indexing rotation frame 113. The central shaft of the drive disk 112 is connected to the output shaft of the rotation motor 111. A drive boss 114 is provided at the edge of the drive disk 112. The central shaft of the indexing rotation frame 113 is coaxially connected to the rotation frame body 12. A plurality of indexing grooves 115 that slide and engage with the drive bosses 114 are evenly distributed along the circumference of the indexing rotation frame 113.

[0032] When the drive boss 114 rotates into the indexing slot 115, it slides and presses against the indexing slot 115, causing the indexing rotating frame 113 to rotate by a specific angle, which in turn causes the rotating frame body 12 to rotate by a specific angle. For example, if the rotating frame body 12 has four sets of lens mounting slots evenly distributed around its circumference, then it only needs to rotate 90° each time to switch to the next lens mounting slot. Therefore, the indexing rotating frame 113 has four indexing slots 115 evenly distributed around its circumference, so that the indexing rotating frame 113 causes the rotating frame body 12 to rotate 90° each time.

[0033] When the drive boss 114 disengages from the indexing groove 115, the indexing groove 115 is no longer under pressure, and the indexing rotating frame 113 stops rotating.

[0034] The other parts of this embodiment are the same as any one of the embodiments 1-3 above, so they will not be described again.

[0035] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A large-aperture fast polarization modulation device, comprising a front rotating frame (1) and a rear rotating frame (2), characterized in that, The front rotating frame (1) is provided with several mirror assembly mounting slots, and the rear rotating frame (2) is provided with several mirror assembly mounting slots; the mirror assembly mounting slots on the front rotating frame (1) are provided with beam shrinking mirror assemblies (3) with different reduction magnifications, and the mirror assembly mounting slots on the rear rotating frame (2) are provided with beam expander mirror assemblies (4) with different magnifications; a polarization modulation component (5) is provided between the beam shrinking mirror assembly (3) and the beam expander mirror assembly (4), and the polarization modulation component (5) includes at least one fixed grating (51) and at least one translation grating (52) that can move along the periodic direction of the fixed grating (51).

2. The large-aperture fast polarization modulation device according to claim 1, characterized in that, A translation device (53) is provided on one side of the translation grating (52). The moving end of the translation device (53) is connected to one side of the translation grating (52) and drives the translation grating (52) to move along the periodic direction.

3. The large-aperture fast polarization modulation device according to claim 2, characterized in that, The translation device (53) includes a high-precision translation motor (531) and a motor controller (532). The motor controller (532) is connected to the high-precision translation motor (531). The translation output shaft of the high-precision translation motor (531) is connected to one side of the translation grating (52) to drive the translation grating (52) to move along the periodic direction.

4. A large-aperture fast polarization modulation device according to any one of claims 1-3, characterized in that, The shrinking magnification of the beam shrinking lens group (3) located at the front and rear ends of the optical axis is the same as the magnification of the beam expanding lens group (4).

5. A large-aperture fast polarization modulation device according to claim 4, characterized in that, The beam shrinking lens group (3) includes a beam shrinking lens frame, on which a first condensing lens (31) and a first collimating lens (32) are arranged sequentially along the optical axis.

6. A large-aperture fast polarization modulation device according to claim 4, characterized in that, The beam expander assembly (4) includes a beam expander frame, on which a second diverging lens (41) and a second collimating lens (42) are arranged sequentially along the optical axis.

7. A large-aperture fast polarization modulation device according to any one of claims 1-3, characterized in that, The front rotating frame (1) includes an indexing rotating device (11) and a rotating frame body (12). The indexing rotating device (11) is connected to the rotating shaft at the center of the rotating frame body (12). Several mirror assembly mounting slots are evenly arranged around the rotating shaft on the rotating frame body (12). The structure of the front rotating frame (1) is the same as that of the rear rotating frame (2).

8. A large-aperture fast polarization modulation device according to claim 7, characterized in that, The indexing rotation device (11) includes a rotating motor (111), a drive disk (112), and an indexing rotation frame (113). The rotating shaft at the center of the drive disk (112) is connected to the output shaft of the rotating motor (111). A drive boss (114) is provided at the edge of the drive disk (112). The rotating shaft at the center of the indexing rotation frame (113) is coaxially connected to the rotation frame body (12). Several indexing grooves (115) that slide and cooperate with the drive boss (114) are evenly distributed along the circumference of the indexing rotation frame (113).

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