Electric polarization controller

Abstract

The utility model belongs to the technical field of optical fiber polarization control, and relates to an electric polarization controller. The electric polarization controller comprises a shell, a plurality of steering engines, a control circuit board and a plurality of optical fiber winding shafts, the shell comprises a first shell and a second shell; the first shell is connected with the second shell; the steering engine is fixed on the first shell; a plurality of flange plates are arranged on the side face of the first shell. Output shafts of the steering engines are horizontally arranged, and the output shafts of all the steering engines are arranged at the same height; the optical fiber winding shaft is provided with an annular groove, and an optical fiber is wound on the annular groove to form a half-wave plate and a quarter-wave plate. According to the utility model, the purpose of polarization control can be realized, the response speed is fast, the performance is stable, the precision and repeatability can be ensured, and the effect of accurate control is realized; and meanwhile, the device has the advantages of low cost, strong durability, good repeatability and easiness in maintenance.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of polarization control technology of optical fiber, concretely relates to a kind of electric polarization controller. BACKGROUND

[0002] In optical measurement, liquid crystal display, 3D image, clinical medicine and communication equipment, etc., it involves the application of light polarization adjusting equipment, and with the rapid development of artificial intelligence technology, people's bandwidth demand for high-speed optical fiber communication equipment is increasing, and silicon photon integrated chip with high integration, great potential for cost reduction, high bandwidth, high-speed transmission and excellent waveguide transmission performance will gradually become the core component of equipment such as optical module and optical switch. However, laser is often introduced into silicon optical chip using edge coupler, and edge coupler is a device that is more sensitive to light of different polarization, and this device has a great impact on the performance of the whole device, so a large number of polarization controllers are often needed to test the performance of the product in mass production.

[0003] Polarization controller is an optical device that can control the input light polarization state. The existing polarization controller mainly includes extruded optical fiber type, rotating wave plate type, electro-optic modulation type and three-ring optical fiber type. Among them, the polarization controller of extruded optical fiber type mainly uses piezoelectric ceramic and other devices to apply external force to the optical fiber in different directions, so as to produce stress birefringence effect to change the polarization state, which has the advantages of simple structure and low cost, but the response speed is slow, the performance is unstable, and accurate control cannot be realized. The rotating wave plate type polarization controller cascades three or more half-wave plates and quarter-wave plates, and rotates the main shaft direction of the wave plate by hand or electrically, so as to introduce birefringence in different directions and achieve the purpose of polarization control. This method is more accurate than extruded optical fiber type, but it is sensitive to wavelength due to the use of wave plate structure. The polarization controller of electro-optic modulation type uses the electro-optic effect of liquid crystal and other crystals to introduce birefringence in different directions to control the polarization state. This method has high precision and fast speed, but the structure is complex, the cost is high, and the wavelength is sensitive. The three-ring type optical fiber polarization controller is most commonly used, which has simple structure and low cost, but it depends on manual operation, and the precision and repeatability are often difficult to guarantee. In addition, in some working conditions, the polarization controller needs to traverse all polarization states, but the above-mentioned manual operation polarization controller structure often does not have the ability to automatically execute the polarization traversal. Although some polarization controllers with electric control function have appeared in recent years, they are often expensive, and the input and output optical IO interfaces are mostly tail fiber type, which is more prone to optical fiber damage and other problems in use. The convenience and durability are not as good as fixed flange type, and the rotating structure is often exposed, which is easy for production line operators to directly touch the rotating shaft, resulting in unstable output polarization state. SUMMARY

[0004] In order to solve the above technical problems, the utility model provides a kind of electric polarization controller, including shell, several rudders, control circuit board and several optical fiber winding shafts;The shell includes first shell and second shell;First shell and second shell are connected;Rudder is fixed on first shell;First shell side is provided with several flanges;The output shaft of rudder is horizontally arranged, and the output shaft of each rudder is arranged at the same height;One end of optical fiber winding shaft is connected in the output end of rudder, and the other end is connected flange;

[0005] Flange and the central axis between the optical fiber of optical fiber winding shaft are provided with rotating shaft, and the output shaft of rudder is located on the same axis line;

[0006] Optical fiber winding shaft is provided with annular groove, and optical fiber is wound on annular groove to form half wave plate and quarter wave plate;

[0007] Control circuit board is fixed on second shell;Second shell is provided with power supply female seat and interface unit;The power line and control signal line of rudder are connected to the solder pad of control circuit board;The power line of control circuit board is connected to power supply female seat;

[0008] Micro development board is fixedly arranged on control circuit board;Micro development board and the control input end of rudder and interface unit are connected.

[0009] On the basis of the above technical scheme, the utility model can also be improved as follows.

[0010] Further, the inner side wall of first shell is provided with limiting mechanism for fixing rudder;The bottom in first shell is provided with optical fiber storage groove.

[0011] Further, first shell is arranged below rudder, and second shell is arranged above rudder, and the side surface of first shell and the side surface of second shell are both provided with screw hole;The side surface of first shell and the side surface of second shell are fixedly connected by screw.

[0012] Further, second shell side is also provided with power interface and program control interface;Power interface and program control interface are electrically connected with micro development board;Rudder is connected with power line, ground wire and signal line;Power line and ground wire are connected with power interface;Signal line is connected with program control interface.

[0013] Further, communication interface is arranged on micro development board.

[0014] Further, each optical fiber winding shaft comprises a swing arm, a gland and an adapter plate; the swing arm is provided with an annular groove and an optical fiber inlet and outlet groove; the gland, the swing arm and one side of the adapter plate are provided with screw holes; the gland and the swing arm are fixedly connected through screws; one side of the adapter plate and the swing arm are fixedly connected through screws; the other side of the adapter plate is provided with a toothed groove; the toothed groove is engaged with the output shaft of the steering engine; one end of the optical fiber inlet and outlet groove close to the adapter plate is an optical fiber outlet, and the other end away from the adapter plate is an optical fiber inlet.

[0015] Further, the annular groove is arranged at the end of the swing arm away from the adapter plate; the annular groove is formed by an annular column, a circular column arranged on the inner side of the annular column and a bottom plate connected with the swing arm; one side of the annular column and the circular column is fixed on the floor; the gland is a circular column structure; the gland is embedded in the annular groove to limit the optical fiber.

[0016] Further, the second shell is provided with a grating type observation window, a state indicating lamp and a reset button; the state indicating lamp and the reset button are electrically connected with the micro development board.

[0017] Further, the first shell is provided with a first flange plate and a second flange plate on the side; the output end of the steering engine is provided with a first optical fiber winding shaft, a second optical fiber winding shaft and a third optical fiber winding shaft; one end of the optical fiber is connected to the first flange plate and enters the first optical fiber winding shaft to form a quarter wave plate; the other end of the optical fiber is connected to the second flange plate and enters the second optical fiber winding shaft to form a quarter wave plate; the optical fiber is placed in the third optical fiber winding shaft to form a half wave plate; the first optical fiber winding shaft, the second optical fiber winding shaft and the third optical fiber winding shaft are fixed on the output shaft of the corresponding steering engine; the optical fiber between the second optical fiber winding shaft and the third optical fiber winding shaft is placed in the optical fiber storage groove.

[0018] The utility model discloses the beneficial effect is:

[0019] (1) the optical fiber winding forms a half wave plate and a quarter wave plate, realizes the purpose of polarization control, and the response speed is fast, and the performance is stable, can guarantee the precision and the repeatability, realizes the effect of accurate control;

[0020] (2) low cost: the whole machine shell and optical fiber winding shaft can directly use 3D additive manufacturing mode production, reduces the opening mould or machining expense;The steering engine is compared with motor, and the price advantage is obvious;It is not necessary to be high in price piezoelectric ceramic or optical wave plate;Directly use finished product micro development board to write drive program, compared with custom-made control circuit also has cost advantage;

[0021] (3) strong durability: all optical fibers are protected in the shell, reducing the risk of direct contact or foreign objects falling into the device, causing the optical fiber to break; the flange plate installed with the optical fiber, the optical fiber winding shaft and the rotating shaft of the steering engine are located on the same straight line, so that when the winding shaft rotates, the optical fiber has no deformation except the twist caused by the polarization itself, prolonging the service life of the optical fiber;

[0022] (4) good repeatability: compared with a manual polarization controller, the utility model can directly send instructions through a micro development board, and set the optical fiber winding shaft to a specific rotation angle;

[0023] (5) easy to maintain: the optical fiber storage groove of the first shell is deep, and can accommodate longer optical fibers, so that the device has no special requirements for the length of the optical fiber used, and any single-mode optical fiber that meets the minimum length can be directly used; all components of the whole machine are fixed by screws or mutual limiting, without any buckle or adhesive area, facilitating disassembly and replacement of damaged parts. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural diagram of an electric polarization controller provided by the utility model;

[0025] Figure 2 is a perspective structural diagram of the electric polarization controller;

[0026] Figure 3 is a structural diagram of a control circuit board;

[0027] Figure 4 is a structural diagram of an optical fiber winding shaft structure;

[0028] Figure 5 is a top view of the internal structure of the electric polarization controller;

[0029] Figure 6 is a top view of the electric polarization controller.

[0030] Icon: 1- steering engine; 101- power line; 102- ground wire; 103- signal line; 2- control circuit board; 3- optical fiber winding shaft; 301- swing arm; 302- gland; 303- adapter plate; 3011- first optical fiber winding shaft; 3012- second optical fiber winding shaft; 3013- third optical fiber winding shaft; 4- first shell; 401- limiting mechanism; 402- optical fiber storage groove; 5- second shell; 501- power interface; 502- program control interface; 503- grating type observation window; 504- status indicator light; 505- reset button; 506- communication interface; 6- flange plate; 601- first flange plate; 602- second flange plate; 7- rotating shaft; 8- annular groove; 9- optical fiber inlet and outlet groove. DETAILED DESCRIPTION

[0031] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0032] Example 1

[0033] As an example, as shown in the attached Figure 1 As shown, to solve the above technical problems, this embodiment provides an electric polarization controller, including a housing, a plurality of servos 1, a control circuit board 2, and a plurality of optical fiber winding shafts 3. The housing includes a first housing 4 and a second housing 5. The first housing 4 and the second housing 5 are connected. The servos 1 are fixed to the first housing 4. A plurality of flanges 6 are provided on the side of the first housing 4. The output shafts of the servos 1 are arranged horizontally, and the output shafts of all servos 1 are arranged at the same height. One end of the optical fiber winding shaft 3 is connected to the output end of the servo 1, and the other end is connected to the flange 6.

[0034] A rotating shaft 7 is provided between the flange 6 and the optical fiber center axis of the optical fiber winding shaft 3. The rotating shaft 7 and the output shaft of the steering gear 1 are located on the same axis.

[0035] An annular groove 8 is provided on the optical fiber winding shaft 3, and the optical fiber is wound on the annular groove 8 to form a half-wave plate and a quarter-wave plate;

[0036] The control circuit board 2 is fixed to the second housing 5; a power socket and an interface unit are provided on the second housing 5; the power line and the control signal line of the servo 1 are connected to the pads of the control circuit board 2; the power line of the control circuit board 2 is connected to the power socket;

[0037] A micro development board 201 is fixedly mounted on the control circuit board 2 ; the micro development board 201 is connected to the control input terminal and the interface unit of the servo 1 .

[0038] During the control circuit layout process, after the servo 1 is installed in the groove on the first shell 4, the control circuit board 2 is installed directly above the servo group using screws. The control circuit board 2 serves as the first limiting mechanism of the servo 1, and bends the signal line of the servo 1 toward the flange 6. A soldering pad is provided on the control circuit board 2, and the signal line is soldered to the control circuit board 2. The power supply of the signal line is connected to the positive pole of the power socket through the control circuit board, and the ground wire is connected to the negative pole of the power socket and the ground pin of the micro development board 201 through the control circuit board 2; the signal line is connected to the three pins of the micro development board 201 respectively through the control circuit board 2; the micro development board 201 and the servo 1 are powered by an interface.

[0039] Optionally, all solder pads of the control circuit board are on one side of the top surface to facilitate soldering operations.

[0040] Optional, as attached Figure 1 As shown, a limiting mechanism 401 for fixing the steering gear 1 is provided on the inner side wall of the first housing 4 ; and an optical fiber receiving groove 402 is provided on the bottom of the first housing.

[0041] Optional, as attached Figure 1 As shown, the first shell 4 is arranged below the servo, and the second shell is arranged above the servo. The side surfaces of the first shell 4 and the second shell 5 are both provided with threaded holes; the side surfaces of the first shell 4 and the second shell 5 are fixedly connected by screws.

[0042] Optional, attached Figure 2 (a) is a schematic diagram of the three-dimensional structure of the electric polarization controller including the flange in the main view, Figure 2 (b) is a schematic diagram of the three-dimensional structure of the electric polarization controller, including a power interface 501 and a programmable interface 502. The second housing 5 also has power interface 501 and programmable interface 502 on its side. These interfaces are electrically connected to the micro development board 201. The servo is connected to a power line 101, a ground line 102, and a signal line 103. The power line 101 and ground line 102 are connected to the power interface 501, and the signal line 103 is connected to the programmable interface 502.

[0043] As attached Figure 3 The control circuit board 2 is arranged above the servo 1. The control circuit board 2 is provided with a micro development board 201, a power interface 501, a status indicator light 504 and a reset button 505.

[0044] Optional, as attached Figure 3 As shown, the micro development board 201 is provided with a communication interface 506 .

[0045] Optional, as attached Figure 4 The optical fiber winding shaft structure shown in the figure, each optical fiber winding shaft includes a swing arm 301, a pressure cover 302 and an adapter plate 303; an annular groove 8 and an optical fiber entry and exit groove 9 are provided on the swing arm 301; screw holes are provided on the pressure cover 302, the swing arm 302 and one side of the adapter plate 303; the pressure cover 302 and the swing arm 301 are fixedly connected by screws; one side of the adapter plate 303 is fixedly connected to the swing arm 301 by screws; a toothed groove is provided on the other side of the adapter plate 303; the toothed groove is engaged with the output shaft of the servo; the end of the optical fiber entry and exit groove 9 close to the adapter plate 303 is the optical fiber outlet, and the end away from the adapter plate 303 is the optical fiber entrance.

[0046] Optionally, the annular groove 8 is arranged at the end of the swing arm 301 away from the adapter plate 303; the annular groove 8 is formed by an annular column, a circular column arranged on the inner side of the annular column, and a base plate connected to the swing arm 301; the annular column and one side of the circular column are fixed to the floor; the pressure cover 302 is a circular column structure; the pressure cover 302 is embedded in the annular groove 8 to limit the optical fiber.

[0047] In actual use, the fiber winding groove and fiber inlet and outlet on the swing arm allow the fiber to be wound several times within the groove. Once the fiber is wound, the gland is screwed to the swing arm to prevent the fiber from scattering and slipping. The adapter plate has a screw hole on one side for connecting to the swing arm with screws, and a toothed groove on the other side that engages with the output shaft of the servo to prevent slipping.

[0048] Optional, as attached Figure 5 The top view of an electric polarization controller is shown. A grid-type observation window 503, a status indicator light 504 and a reset button 505 are provided on the second housing. The status indicator light 504 and the reset button 505 are electrically connected to the micro development board.

[0049] In actual application, the second shell has three sets of grid-type observation windows, which are convenient for observing the operating status of each optical fiber winding axis. The second shell has through holes at the corresponding positions of the status indicator light and the reset button of the micro development board. When the device is powered on, the status indicator light is green; when the device is performing a polarization traversal task, or running to the set angle, the indicator light is blue; when it is necessary to terminate the running task, an instruction is sent to the micro development board through the data interface. At this time, the device will stop running, the three sets of optical fiber winding axes will stop at the current position, and the status indicator light will be red. When it is necessary to perform the polarization traversal task again, an initialization instruction can be sent to the development board through the data interface, or the reset button can be pressed directly. At this time, the angles of the three sets of optical fiber winding axes will return to the initial position, and the status indicator light will be green.

[0050] Optional, as attached Figure 6 A top view of the internal structure of an electric polarization controller is shown. A first flange 601 and a second flange 602 are provided on the side of the first housing 4. A first fiber winding shaft 3011, a second fiber winding shaft 3012, and a third fiber winding shaft 3013 are provided at the output end of the servo 1. One end of the optical fiber connects to the first flange 601 and is wound into the first fiber winding shaft 3011 to form a quarter-wave plate. The other end of the optical fiber connects to the second flange 6 and is wound into the second fiber winding shaft 3012 to form a quarter-wave plate. The optical fiber is placed in the third fiber winding shaft 3013 and is wound into a half-wave plate. The first, second, and third fiber winding shafts 3011, 3012, and 3013 are each fixed to the output shaft of the corresponding servo 1. The optical fiber between the second and third fiber winding shafts 3012, 3013, is placed in the fiber receiving slot 402.

[0051] In the process of fiber arrangement, the optical fiber selects a double-joint single-mode optical fiber, one end of the optical fiber is connected to the first flange plate (601) and enters the first optical fiber winding shaft 3011 to form a quarter-wave plate, the other end of the optical fiber is connected to the second flange plate (602) and enters the second optical fiber winding shaft 3012 to form a quarter-wave plate, the optical fiber is placed in the third optical fiber winding shaft 3013 to form a half-wave plate, the first optical fiber winding shaft 3011, the second optical fiber winding shaft 3012 and the third optical fiber winding shaft 3013 are fixed on the output shaft of the corresponding steering engine 1, the remaining optical fiber between the first optical fiber winding shaft 3011 and the second optical fiber winding shaft 3012 is arranged in the optical fiber storage groove 402, the remaining optical fiber between the second optical fiber winding shaft 3012 and the third optical fiber winding shaft 3013 is arranged in the optical fiber storage groove 402, and the optical fiber installation is completed.

[0052] In actual application, the flange plate uses a narrow key flange to improve the repeatability of the equipment. The narrow key flange is used, and the cooperation accuracy with the ceramic ferrule is higher, so that the insertion loss fluctuation caused by multiple plugging and unplugging can be effectively reduced.

[0053] Optionally, the edge of the optical fiber storage groove of the first shell is provided with a chamfer, which can reduce the risk of breakage of the optical fiber caused by abrasion.

[0054] In the operation process of the electric polarization controller, first, the light source and the device to be measured are connected to the flange plate on the shell through the optical fiber, and then the PC sends instructions such as "scanning" or "resetting" or setting the polarization angle to the micro development board through the USB data connection line, at this time, the pins of the development board send signals to each group of steering engines to control the steering engines to continuously operate or rotate to the set angle, and the polarization scanning or setting is completed.

[0055] The utility model has the following advantages:

[0056] (1) The optical fiber is wound to form a half-wave plate and a quarter-wave plate, the purpose of polarization control is achieved, the response speed is fast, the performance is stable, the accuracy and repeatability can be guaranteed, and the effect of accurate control is realized.

[0057] (2) Low cost: the whole machine shell and the optical fiber winding shaft can be directly produced by using 3D additive manufacturing method, the mold opening or machining cost is reduced; compared with the motor, the price advantage of the steering engine is obvious; the expensive piezoelectric ceramic or optical wave plate is not needed; the finished micro development board is directly used to write the driving program, and compared with the customized control circuit, the cost advantage is also obvious.

[0058] (3) Strong durability: all optical fibers are protected in the shell, reducing the risk of optical fiber breakage caused by direct touch or foreign objects falling into the device; the flange plate installed with optical fibers, the optical fiber winding shaft and the rotating shaft of the steering engine are located on the same straight line, so when the winding shaft rotates, the optical fiber has no deformation except the twist caused by polarization itself, prolonging the service life of the optical fiber;

[0059] (4) Good repeatability: compared with a manual polarization controller, the utility model can directly send instructions through a micro development board to set the optical fiber winding shaft to a specific rotation angle;

[0060] (5) Easy to maintain: the optical fiber storage groove of the first shell has a large depth and can accommodate longer optical fibers, so the device has no special requirements for the length of the optical fiber used, and any single-mode optical fiber that meets the minimum length can be directly used; all components of the whole machine are fixed by screws or mutual limiting, without any buckle or adhesive area, facilitating disassembly and replacement of damaged components.

[0061] The above is only the preferred embodiment of the utility model and is not used to limit the utility model. For those skilled in the art, the utility model can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model shall be included in the protection scope of the utility model.

Claims

1. An electrically powered polarization controller characterized by, The application relates to a fiber winding device, which comprises a shell, a plurality of rudders (1), a control circuit board (2) and a plurality of fiber winding shafts (3); the shell comprises a first shell (4) and a second shell (5); the first shell (4) is connected with the second shell (5); the rudders (1) are fixed on the first shell (4); a plurality of flanges (6) are arranged on the side of the first shell (4); the output shafts of the rudders (1) are horizontally arranged and arranged at the same height; one end of the fiber winding shaft (3) is connected with the output end of the rudder (1), and the other end is connected with the flange (6). A rotating shaft (7) is arranged between the flange (6) and the central shaft of the fiber winding shaft (3); the rotating shaft (7) is located on the same axis as the output shaft of the rudder (1). An annular groove (8) is arranged on the fiber winding shaft (3); the fiber is wound on the annular groove (8) to form a half-wave plate and a quarter-wave plate. The control circuit board (2) is fixed on the second shell (5); a power supply socket and an interface unit are arranged on the second shell (5); the power supply line and the control signal line of the rudder (1) are connected to the solder pad of the control circuit board (2); the power supply line of the control circuit board (2) is connected to the power supply socket. A micro development board (201) is fixedly arranged on the control circuit board (2); the micro development board (201) is connected with the control input end of the rudder (1) and the interface unit.

2. The electrically powered polarization controller of claim 1, wherein, A limiting mechanism (401) for fixing the rudder (1) is arranged on the inner side wall of the first shell (4); a fiber storage groove (402) is arranged on the bottom of the first shell (4).

3. The electrically powered polarization controller of claim 1, wherein, The first shell (4) is arranged below the rudder (1), the second shell (5) is arranged above the rudder (1), screw holes are arranged on the side of the first shell (4) and the side of the second shell (5); the side of the first shell (4) and the side of the second shell (5) are fixedly connected through screws.

4. The electrically powered polarization controller of claim 1, wherein, A power supply interface and a program control interface are further arranged on the side of the second shell (5); the power supply interface and the program control interface are electrically connected with the micro development board (201); the rudder (1) is connected with a power supply line, a ground wire and a signal line; the power supply line and the ground wire are connected with the power supply interface; the signal line is connected with the program control interface.

5. The electrically powered polarization controller of claim 1, wherein, A communication interface (506) is arranged on the micro development board (201).

6. The electrically powered polarization controller of claim 1, wherein, Each fiber winding shaft (3) comprises a swing arm (301), a gland (302) and an adapter plate (303); the swing arm (301) is provided with an annular groove and a fiber inlet and outlet groove; screw holes are arranged on one side of the gland (302), the swing arm (301) and the adapter plate (303); the gland (302) and the swing arm (301) are fixedly connected through screws; one side of the adapter plate (303) and the swing arm (301) are fixedly connected through screws; the other side of the adapter plate (303) is provided with a toothed groove; the toothed groove is engaged with the output shaft of the rudder (1); one end of the fiber inlet and outlet groove close to the adapter plate (303) is a fiber outlet, and the other end away from the adapter plate (303) is a fiber inlet.

7. The electrically powered polarization controller of claim 5, wherein, The annular groove (8) is arranged at the end of the swing arm (301) away from the adapter plate (303); the annular groove (8) is formed by an annular column, a circular column arranged on the inner side of the annular column and a bottom plate connected with the swing arm (301); the annular column and one side of the circular column are fixed on the floor; the gland (302) is a circular column structure; the gland (302) is embedded in the annular groove (8) to limit the optical fiber.

8. The electrically powered polarization controller of claim 1, wherein, The second shell (5) is provided with a grating type observation window (503), a state indicating lamp (504) and a reset button (505); the state indicating lamp and the reset button are electrically connected with the micro development board (201).

9. The electrically powered polarization controller of claim 2, wherein, The first shell (4) is provided with a first flange plate (601) and a second flange plate (602) on the side; the output end of the steering engine (1) is provided with a first optical fiber winding shaft (3011), a second optical fiber winding shaft (3012) and a third optical fiber winding shaft (3013); one end of the optical fiber is connected to the first flange plate (601) and enters the first optical fiber winding shaft (3011) to form a quarter wave plate; the other end of the optical fiber is connected to the second flange plate (6) and enters the second optical fiber winding shaft (3012) to form a quarter wave plate; the optical fiber is placed in the third optical fiber winding shaft (3013) to form a half wave plate; the first optical fiber winding shaft (3011), the second optical fiber winding shaft (3012) and the third optical fiber winding shaft (3013) are fixed on the corresponding output shaft of the steering engine (1); the optical fiber between the second optical fiber winding shaft (3012) and the third optical fiber winding shaft (3013) is placed in the optical fiber storage groove (402).

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