Fast and Accurate Polarization Alignment Device and Method

Abstract

The present invention provides a fast and accurate polarization alignment device and method. The device includes a light source, a coupling stage, and an extinction ratio tester: the output end of the light source is connected to the input end of the Y waveguide; a coupling part is provided on the coupling stage, the first output end or the second output end of the Y waveguide is fixed to the first end of the coupling part, and a scale value is provided on the second end of the coupling part; when the first end of the optical fiber loop is connected to the second end of the coupling part, the input end of the extinction ratio tester is connected to the second end of the optical fiber loop to measure the relationship between the extinction ratio of the light beam output from the second end of the optical fiber loop and the scale value corresponding to the first end of the optical fiber loop; when the second end of the optical fiber loop is connected to the second end of the coupling part, the input end of the extinction ratio tester is connected to the first end of the optical fiber loop to measure the relationship between the extinction ratio of the light beam output from the first end of the optical fiber loop and the scale value corresponding to the second end of the optical fiber loop. The above solution can achieve the polarization alignment between the Y waveguide and the optical fiber loop with high efficiency and high accuracy, and can be achieved without expensive equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic devices, and particularly to a fast and accurate polarization alignment device and method. Background Art

[0002] The fiber optic gyroscope is an inertial navigation fiber optic sensor based on the Sagnac effect. Its application fields are constantly expanding, the technology is constantly maturing and progressing, and the product reliability is also gradually improving. Currently, the fiber optic gyroscope is mainly developing towards high precision and high reliability.

[0003] Reference Figure 1 , in the fiber optic ring of the fiber optic gyroscope system, the fiber optic sensing ring includes a Y waveguide 101 and a fiber optic ring 102, and it is necessary to fuse and connect the Y waveguide 101 and the fiber optic ring 102. Currently, the connection is mainly made by fusing with a polarization maintaining fiber optic splicer. Relying on the polarization maintaining fiber optic splicer to fuse the output end of the Y waveguide device and the fiber optic ring to form a sensitive ring module will introduce splicing loss during the splicing process, reducing the performance of the fiber optic gyroscope system; during the splicing process, handling the fiber will cause the fiber to be crushed, resulting in a decrease in the fiber tensile force after splicing, causing a reliability risk for the fiber optic gyroscope; the polarization maintaining splicer applies the fiber side imaging method and performs splicing by finding the geometric axis of the fiber. However, there is often a deviation between the geometric axis of the fiber and the optical polarization axis of the fiber, resulting in a decrease in the polarization maintaining performance of the fiber after splicing; after the fiber is spliced, a protective glue needs to be applied at the melting point, which will cause stress mismatch with the original coating layer of the fiber, resulting in the phenomenon of optical polarization axis deflection; and a part of the fiber will be consumed during splicing, affecting the symmetry of the fiber optic ring. These problems restrict the development of the fiber optic gyroscope towards high precision and high reliability.

[0004] To solve the above problems and further improve the performance of the fiber optic gyroscope system, the direct coupling method of the two ends of the fiber optic ring with the Y waveguide is usually adopted. Specifically, reference can be made to: Chinese Patent Application No. 201410602250.2, titled: Polarization axis alignment on-line detection device and on-line measurement method for direct coupling of polarization maintaining fiber optic ring and Y waveguide. Although the fiber alignment method of the sensitive ring module applied in this patent is efficient, since the sensitive ring module still couples by determining the geometric axis of the fiber, there may still be a deviation between the geometric polarization axis of the fiber stress area and the optical polarization axis of the fiber, thus affecting the axis alignment accuracy; another method is to directly test the polarization crosstalk at the coupling point through OCDP (white light interferometer) to determine whether the polarization axis of the chip is aligned with the fiber polarization axis. Although this method has simple equipment, high test accuracy and measurement precision, the test time of OCDP is relatively long (optical path scanning time), and the equipment is also very expensive, which is not conducive to the mass production of sensitive ring modules. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that there are problems of low polarization alignment efficiency, inaccuracy, and high cost when the Y waveguide is coupled with the fiber optic loop in the prior art, and further provides a fast and accurate polarization alignment device and method.

[0006] To this end, the present invention provides a fast and accurate polarization alignment device for realizing the polarization alignment between the Y waveguide and the fiber optic loop, including a light source, a coupling stage, and an extinction ratio tester:

[0007] The output end of the light source is connected to the input end of the Y waveguide; a coupling part is provided on the coupling stage, the first output end or the second output end of the Y waveguide is fixed to the first end of the coupling part, and a scale value is provided at the second end of the coupling part;

[0008] When the first end of the fiber optic loop is connected to the second end of the coupling part, the input end of the extinction ratio tester is connected to the second end of the fiber optic loop to measure the relationship between the extinction ratio of the light beam output from the second end of the fiber optic loop and the scale value corresponding to the first end of the fiber optic loop; when the second end of the fiber optic loop is connected to the second end of the coupling part, the input end of the extinction ratio tester is connected to the first end of the fiber optic loop to measure the relationship between the extinction ratio of the light beam output from the first end of the fiber optic loop and the scale value corresponding to the second end of the fiber optic loop.

[0009] Optionally, in the above fast and accurate polarization alignment device, a first pigtail head is provided at the end of the first end of the fiber optic loop, and a second pigtail head is provided at the end of the second end of the fiber optic loop; the first end of the fiber optic loop is connected to the second end of the coupling part or the input end of the extinction ratio tester through the first pigtail head; the second end of the fiber optic loop is connected to the second end of the coupling part or the input end of the extinction ratio tester through the second pigtail head.

[0010] Optionally, in the above fast and accurate polarization alignment device, the light source includes a low polarization light source.

[0011] Optionally, in the above fast and accurate polarization alignment device, the light source further includes a coupler and a first optical power meter;

[0012] The output end of the low polarization light source is connected to the first end of the coupler, and the output end of the coupler is used as the output end of the light source and is connected to the input end of the Y waveguide;

[0013] The first optical power meter is connected to the second end of the coupler to measure the optical power value of the light beam emitted by the low polarization light source;

[0014] The device further includes a second optical power meter. When the first fiber optic pigtail head is connected to the second end of the coupling part, the input end of the second optical power meter is connected to the second fiber optic pigtail head to measure the power value of the light beam output from the second fiber optic pigtail head; when the second fiber optic pigtail head is connected to the second end of the coupling part, the input end of the second optical power meter is connected to the first fiber optic pigtail head to measure the power value of the light beam output from the first fiber optic pigtail head.

[0015] Optionally, for the above-mentioned fast and accurate polarization alignment device, two coupling parts are provided on the coupling table, and the positional relationship between the two coupling parts is adapted to the positional relationship between the first output end and the second output end of the Y waveguide.

[0016] The present invention also provides a fast and accurate polarization alignment method, which is implemented by the fast and accurate polarization alignment device according to any of the above solutions, and includes the following steps:

[0017] Connect the input end of the Y waveguide to the output end of the light source in the device;

[0018] Connect the first output end of the Y waveguide to the first end of the coupling part on the coupling table; connect the first end of the optical fiber loop to the second end of the coupling part, and connect the second end of the optical fiber loop to the input end of the extinction ratio tester; adjust the alignment angle between the first end of the optical fiber loop and the coupling part, and record in real time the scale value on the second end of the coupling part corresponding to the first end of the optical fiber loop, and at the same time record the extinction ratio of the light beam output from the second end of the optical fiber loop measured by the extinction ratio tester; determine the first optimal alignment angle for the docking of the first end of the optical fiber loop and the coupling part according to the relationship between the extinction ratio of the light beam output from the second end of the optical fiber loop and the scale value corresponding to the first end of the optical fiber loop;

[0019] Connect the second output end of the Y waveguide to the first end of the coupling part on the coupling table; connect the second end of the optical fiber loop to the second end of the coupling part, and connect the first end of the optical fiber loop to the input end of the extinction ratio tester; adjust the alignment angle between the second end of the optical fiber loop and the coupling part, and record in real time the scale value on the second end of the coupling part corresponding to the first end of the optical fiber loop, and at the same time record the extinction ratio of the light beam output from the first end of the optical fiber loop measured by the extinction ratio tester; determine the second optimal alignment angle for the docking of the second end of the optical fiber loop and the coupling part according to the relationship between the extinction ratio of the light beam output from the first end of the optical fiber loop and the scale value corresponding to the second end of the optical fiber loop;

[0020] Couple the first output end of the Y waveguide and the first end of the optical fiber loop after docking at the first optimal angle; couple the second output end of the Y waveguide and the second end of the optical fiber loop after docking at the second optimal angle.

[0021] Optionally, for the above-mentioned fast and accurate polarization alignment method, the first optimal angle is determined as follows: during the process of adjusting the alignment angle between the first end of the optical fiber loop and the coupling part, the first moment and the second moment when the extinction ratio measured by the extinction ratio tester changes are obtained; the first scale value corresponding to the first end of the optical fiber loop at the first moment is obtained, and the second scale value corresponding to the first end of the optical fiber loop at the second moment is obtained; the average value of the first scale value and the second scale value is used as the first optimal angle;

[0022] The second optimal angle is determined as follows: during the process of adjusting the alignment angle between the second end of the optical fiber loop and the coupling part, the third moment and the fourth moment when the extinction ratio measured by the extinction ratio tester changes are obtained; the third scale value corresponding to the second end of the optical fiber loop at the third moment is obtained, and the fourth scale value corresponding to the second end of the optical fiber loop at the fourth moment is obtained; the average value of the third scale value and the fourth scale value is used as the second optimal angle.

[0023] Optionally, the above-mentioned fast and accurate polarization alignment method further includes:

[0024] Connect the output end of the coupler in the light source to the input end of the Y waveguide;

[0025] Connect the second optical power meter to the second end of the optical fiber loop; according to the optical power value of the beam emitted by the low-bias light source measured by the first optical power in the light source and the optical power value of the beam output from the second end of the optical fiber loop measured by the second optical power meter, determine the first optimal coupling position between the first end of the optical fiber loop and the first output end of the Y waveguide;

[0026] Connect the second optical power meter to the first end of the optical fiber loop; according to the optical power value of the beam emitted by the low-bias light source measured by the first optical power in the light source and the optical power value of the beam output from the first end of the optical fiber loop measured by the second optical power meter, determine the second optimal coupling position between the second end of the optical fiber loop and the second output end of the Y waveguide.

[0027] Optionally, for the above-mentioned fast and accurate polarization alignment method, the first optimal coupling position and the second optimal coupling position satisfy:

[0028] The difference between the optical power value of the beam output from the first end of the optical fiber loop and the optical power value of the beam output from the second end of the optical fiber loop is within the allowable range.

[0029] Compared with the prior art, the above technical solution provided by the embodiment of the present invention has at least the following beneficial effects:

[0030] The fast and accurate polarization alignment device and method provided by the present invention can, when one end of the Y waveguide is connected to the fiber optic loop, use the other end of the fiber optic loop as the output, and determine whether polarization alignment is achieved between the Y waveguide and one end of the fiber optic loop by measuring the extinction ratio of the output light beam. Thus, polarization alignment between the Y waveguide and the fiber optic loop can be achieved with high efficiency and high accuracy, and it can be achieved without expensive equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the coupling relationship between the Y waveguide and the fiber optic loop in a fiber optic gyroscope;

[0032] Figure 2a and 2b It is a schematic structural diagram of the fast and accurate polarization alignment device according to an embodiment of the present invention;

[0033] Figure 3 It is a schematic structural diagram of the fast and accurate polarization alignment device according to another embodiment of the present invention;

[0034] Figure 4 It is a schematic diagram of the correspondence between the measurement result of the extinction ratio tester and the optimal angle according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The embodiments of the present invention will be further described below with reference to the accompanying drawings. In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of simplifying the description of the present invention, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0036] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, 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 directly connected, or indirectly connected 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 the present invention can be understood according to specific situations.

[0037] For each of the technical solutions in the following embodiments provided by the present invention, unless they are mutually contradictory to each other, different technical solutions can be combined with each other, and the technical features in different solutions can be replaced with each other.

[0038] Embodiment 1

[0039] This embodiment provides a fast and accurate polarization alignment device for realizing the polarization alignment between the Y waveguide 203 and the fiber optic loop 204, as Figure 2a and 2b shown, which includes a light source 201, a coupling stage (not shown), and an extinction ratio tester 202. The output end of the light source 201 is connected to the input end 1 of the Y waveguide 203; a coupling part is provided on the coupling stage, the first output end or the second output end of the Y waveguide is fixed to the first end of the coupling part, a scale value is provided on the second end of the coupling part, and the second end of the coupling part may have a circular edge, then a plurality of scale values are provided on the circular edge, and the scale values can be marked from 0 degree to 360 degrees. When the first end 2 of the fiber optic loop is connected to the second end of the coupling part, the input end of the extinction ratio tester 202 is connected to the second end 3 of the fiber optic loop to measure the relationship between the extinction ratio of the light beam output from the second end of the fiber optic loop and the scale value corresponding to the first end 2 of the fiber optic loop; when the second end 3 of the fiber optic loop 204 is connected to the second end of the coupling part, the input end of the extinction ratio tester is connected to the first end 2 of the fiber optic loop to measure the relationship between the extinction ratio of the light beam output from the first end 2 of the fiber optic loop and the scale value corresponding to the second end 3 of the fiber optic loop.

[0040] The above solution can, when one end of the Y waveguide 203 is connected to one end of the fiber optic loop 204, use the other end of the fiber optic loop 204 as the output, and determine whether the polarization alignment between the Y waveguide 203 and one end of the fiber optic loop 204 is achieved by measuring the extinction ratio of the output light beam. Thus, the polarization alignment between the Y waveguide 203 and the fiber optic loop 204 can be achieved with high efficiency and high accuracy, and it can be achieved without expensive equipment.

[0041] In the above solution, a first pigtail head is provided at the end of the first end 2 of the fiber optic loop, and a second pigtail head is provided at the end of the second end 3 of the fiber optic loop; the first end 2 of the fiber optic loop is connected to the second end of the coupling part or the input end of the extinction ratio tester 202 through the first pigtail head; the second end 3 of the fiber optic loop is connected to the second end of the coupling part or the input end of the extinction ratio tester 202 through the second pigtail head. The pigtail head can be made by means of fixed axis and grinding.

[0042] Further, referring to Figure 3, the light source includes a low polarization light source 205, and also includes a coupler 206 and a first optical power meter 207; the output end of the low polarization light source 205 is connected to the first end of the coupler 206, and the output end of the coupler 206 serves as the output end of the light source and is connected to the input end of the Y waveguide 203; the first optical power meter 207 is connected to the second end of the coupler 206 to measure the optical power value of the light beam emitted by the low polarization light source 205; the device further includes a second optical power meter 208. When the first fiber optic pigtail is connected to the second end of the coupling part, the input end of the second optical power meter 208 is connected to the second fiber optic pigtail to measure the power value of the light beam output by the second fiber optic pigtail; when the second fiber optic pigtail is connected to the second end of the coupling part, the input end of the second optical power meter 208 is connected to the first fiber optic pigtail to measure the power value of the light beam output by the first fiber optic pigtail. Accordingly, reference can be made to Figure 2a and Figure 2b the relationship between Figure 3 the shown connection relationship is adjusted to measure the power value at the other end of the fiber optic loop.

[0043] In the above solution, active alignment is performed by the low polarization light source 205. After passing through the Y waveguide 203 (a high polarization chip that can polarize the light beam output by the low polarization light source) and directly coupling into the fiber optic loop, fiber optic axis alignment is carried out, which is beneficial to improving the accuracy of the optical polarization axis direction. The device is more suitable for the fiber optic gyroscope system and has a high axis alignment efficiency.

[0044] In the above solution, two coupling parts can be provided on the coupling table, and the positional relationship between the two coupling parts is adapted to the positional relationship between the first output end and the second output end of the Y waveguide. Thus, when the Y waveguide is placed on the coupling table, the two output ends of the Y waveguide can be respectively connected to the two coupling parts, further simplifying the structure of the device and facilitating operation.

[0045] Embodiment 2

[0046] This embodiment provides a method for fast and accurate polarization alignment, which is realized by the fast and accurate polarization alignment device according to any solution of Embodiment 1, and includes the following steps:

[0047] Step 1: Connect the input end of the Y waveguide to the output end of the light source in the device;

[0048] Step 2: Refer to Figure 2a, connect the first output end of the Y waveguide to the first end of the coupling part on the coupling table; connect the first end of the optical fiber loop to the second end of the coupling part, and connect the second end of the optical fiber loop to the input end of the extinction ratio tester; adjust the alignment angle between the first end of the optical fiber loop and the coupling part, and record in real time the scale value on the second end of the coupling part corresponding to the first end of the optical fiber loop, and at the same time record the extinction ratio of the light beam output from the second end of the optical fiber loop measured by the extinction ratio tester; determine the first optimal alignment angle between the first end of the optical fiber loop and the coupling part according to the relationship between the extinction ratio of the light beam output from the second end of the optical fiber loop and the scale value corresponding to the first end of the optical fiber loop;

[0049] Step 3: Refer to Figure 2b , connect the second output end of the Y waveguide to the first end of the coupling part on the coupling table; connect the second end of the optical fiber loop to the second end of the coupling part, and connect the first end of the optical fiber loop to the input end of the extinction ratio tester; adjust the alignment angle between the second end of the optical fiber loop and the coupling part, and record in real time the scale value on the second end of the coupling part corresponding to the first end of the optical fiber loop, and at the same time record the extinction ratio of the light beam output from the first end of the optical fiber loop measured by the extinction ratio tester; determine the second optimal alignment angle between the second end of the optical fiber loop and the coupling part according to the relationship between the extinction ratio of the light beam output from the first end of the optical fiber loop and the scale value corresponding to the second end of the optical fiber loop;

[0050] Step 4: Couple the first output end of the Y waveguide and the first end of the optical fiber loop after docking at the first optimal angle; couple the second output end of the Y waveguide and the second end of the optical fiber loop after docking at the second optimal angle.

[0051] In the above solution, when one end of the Y waveguide is connected to the optical fiber loop, the other end of the optical fiber loop is used as the output. By measuring the extinction ratio of the output light beam, it can be judged whether the polarization alignment between the Y waveguide and one end of the optical fiber loop is achieved. Thus, the polarization alignment between the Y waveguide and the optical fiber loop can be realized with high efficiency and high accuracy, and it can be realized without expensive equipment.

[0052] Further, the first optimal angle is determined in the following manner: During the process of adjusting the alignment angle between the first end of the optical fiber loop and the coupling portion, the first moment and the second moment when the extinction ratio measured by the extinction ratio tester changes are obtained; the first scale value corresponding to the first end of the optical fiber loop at the first moment is obtained, and the second scale value corresponding to the first end of the optical fiber loop at the second moment is obtained; the average value of the first scale value and the second scale value is used as the first optimal angle; the second optimal angle is determined in the following manner: During the process of adjusting the alignment angle between the second end of the optical fiber loop and the coupling portion, the third moment and the fourth moment when the extinction ratio measured by the extinction ratio tester changes are obtained; the third scale value corresponding to the second end of the optical fiber loop at the third moment is obtained, and the fourth scale value corresponding to the second end of the optical fiber loop at the fourth moment is obtained; the average value of the third scale value and the fourth scale value is used as the second optimal angle.

[0053] Reference Figure 4 , after connecting one end of the optical fiber loop to the coupling portion, first adjust the polarization axis of one end of the optical fiber loop. Since depolarization of the optical fiber loop causes the extinction ratio of the light beam output from the other end of the optical fiber loop to be a fixed value within a certain scale value range, by rotating the docking angle scale value between one end of the optical fiber loop and the second end of the coupling portion, the two scale values corresponding to the change in the extinction ratio are respectively: θ′, θ″, then θ = (θ′ + θ″) / 2 is the optimal angle, and record θ; find the optimal angles at both ends of the optical fiber by this method and perform the coupling operation. It can be understood that the specific method of the coupling operation can refer to the solutions of the prior art, such as the specific operation steps of dispensing and exposure.

[0054] In addition, the above solution may further include the following steps:

[0055] Step A: Connect the output end of the coupler in the light source to the input end of the Y waveguide.

[0056] Step B: Reference Figure 3 , connect the second optical power meter to the second end of the optical fiber loop; according to the optical power value of the light beam emitted by the low-bias light source measured by the first optical power in the light source and the optical power value of the light beam output from the second end of the optical fiber loop measured by the second optical power meter, determine the first optimal coupling position between the first end of the optical fiber loop and the first output end of the Y waveguide.

[0057] Step C: Connect the second optical power meter to the first end of the optical fiber loop; according to the optical power value of the light beam emitted by the low-bias light source measured by the first optical power in the light source and the optical power value of the light beam output from the first end of the optical fiber loop measured by the second optical power meter, determine the second optimal coupling position between the second end of the optical fiber loop and the second output end of the Y waveguide.

[0058] Taking step B as an example, the core at the first end of the optical fiber loop needs to be aligned with the center of the first output end of the Y waveguide. At this time, the loss generated when the Y waveguide and the optical fiber loop are coupled together can be obtained according to the power value of the output beam of the low-bias light source measured by the first optical power meter and the optical power value of the output beam at the second end of the optical fiber loop. The position with the minimum loss value can be considered as the optimal coupling position, that is, at this time, the core at the first end of the optical fiber loop corresponds more accurately to the center of the first output end of the Y waveguide. Correspondingly, the alignment of the second end of the optical fiber loop with the second output end of the Y waveguide can also be achieved with reference to the above scheme. The above steps can be implemented before polarization alignment.

[0059] Preferably, in the above scheme, the first optimal coupling position and the second optimal coupling position satisfy that the difference between the optical power value of the output beam at the first end of the optical fiber loop and the optical power value of the output beam at the second end of the optical fiber loop is within an allowable range. Theoretically, after the two output ends of the Y waveguide are coupled with the two ends of the optical fiber loop, the optical transmission parameters at the two coupling points should be consistent, that is, it is best to have the same optical power loss. Even if it cannot be completely equal, it is hoped that the difference in optical power loss between the two coupling points is within an allowable range, for example, the difference is within 5 dB.

[0060] The sensitive ring module obtained by coupling the Y waveguide with the optical fiber loop using the above method is tested, and its optical parameters are shown in Table 1:

[0061] Table 1 Test data of the sensitive ring module

[0062] Optical fiber loop crosstalk -23 dB Two-port pigtail polarization crosstalk -22.5 dB Three-port pigtail polarization crosstalk -23.1 dB

[0063] After truncating the Y waveguide output end of the sensitive ring module obtained by coupling the Y waveguide with the optical fiber loop using the above method, parameters such as polarization crosstalk, splitting ratio, and insertion loss of the pigtail at the Y waveguide output end are tested. The test parameters are shown in Table 2.

[0064] Table 2 Test data of the Y waveguide after truncating the sensitive ring module

[0065] Loss 2.5 dB Beam splitting ratio 49.7 / 50.3 Two-port pigtail polarization crosstalk -38.6 dB Three-port pigtail polarization crosstalk -32.9 dB

[0066] According to the test data shown in Table 1 and Table 2, it can be shown that the polarization alignment result of coupling the Y waveguide with the optical fiber loop using the above method has high accuracy.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fast and accurate polarization alignment method, implemented by a fast and accurate polarization alignment device, characterized in that: The fast and accurate polarization alignment device includes a light source, a coupling stage, and an extinction ratio tester: The output end of the light source is connected to the input end of the Y waveguide; a coupling part is provided on the coupling stage, the first output end or the second output end of the Y waveguide is fixed to the first end of the coupling part, and a scale value is provided on the second end of the coupling part; When one end of the fiber loop is connected to the Y waveguide and the other end of the fiber loop is used as the output, it is judged whether polarization alignment is achieved between the Y waveguide and one end of the fiber loop by measuring the extinction ratio of the output light beam, including: When the first end of the fiber loop is connected to the second end of the coupling part, the input end of the extinction ratio tester is connected to the second end of the fiber loop to measure the relationship between the extinction ratio of the output light beam at the second end of the fiber loop and the scale value corresponding to the first end of the fiber loop; when the second end of the fiber loop is connected to the second end of the coupling part, the input end of the extinction ratio tester is connected to the first end of the fiber loop to measure the relationship between the extinction ratio of the output light beam at the first end of the fiber loop and the scale value corresponding to the second end of the fiber loop; The method includes the following steps: Connect the input end of the Y waveguide to the output end of the light source in the device; Connect the first output end of the Y waveguide to the first end of the coupling part on the coupling stage; connect the first end of the fiber loop to the second end of the coupling part, and connect the second end of the fiber loop to the input end of the extinction ratio tester; adjust the alignment angle between the first end of the fiber loop and the coupling part, and record in real time the scale value on the second end of the coupling part corresponding to the first end of the fiber loop, and at the same time record the extinction ratio of the output light beam at the second end of the fiber loop measured by the extinction ratio tester; determine the first optimal angle for the first end of the fiber loop to dock with the coupling part according to the relationship between the extinction ratio of the output light beam at the second end of the fiber loop and the scale value corresponding to the first end of the fiber loop; Connect the second output end of the Y waveguide to the first end of the coupling part on the coupling stage; connect the second end of the fiber loop to the second end of the coupling part, and connect the first end of the fiber loop to the input end of the extinction ratio tester; adjust the alignment angle between the second end of the fiber loop and the coupling part, and record in real time the scale value on the second end of the coupling part corresponding to the first end of the fiber loop, and at the same time record the extinction ratio of the output light beam at the first end of the fiber loop measured by the extinction ratio tester; determine the second optimal angle for the second end of the fiber loop to dock with the coupling part according to the relationship between the extinction ratio of the output light beam at the first end of the fiber loop and the scale value corresponding to the second end of the fiber loop; Couple the first output end of the Y waveguide and the first end of the fiber loop after docking at the first optimal angle; couple the second output end of the Y waveguide and the second end of the fiber loop after docking at the second optimal angle; The first optimal angle is determined as follows: during the process of adjusting the alignment angle between the first end of the optical fiber loop and the coupling part, obtain the first moment and the second moment when the extinction ratio measured by the extinction ratio tester changes; obtain the first scale value corresponding to the first end of the optical fiber loop at the first moment, and obtain the second scale value corresponding to the first end of the optical fiber loop at the second moment; take the average value of the first scale value and the second scale value as the first optimal angle; The second optimal angle is determined as follows: during the process of adjusting the alignment angle between the second end of the optical fiber loop and the coupling part, obtain the third moment and the fourth moment when the extinction ratio measured by the extinction ratio tester changes; obtain the third scale value corresponding to the second end of the optical fiber loop at the third moment, and obtain the fourth scale value corresponding to the second end of the optical fiber loop at the fourth moment; take the average value of the third scale value and the fourth scale value as the second optimal angle; Connect the output end of the coupler in the light source to the input end of the Y waveguide; Connect the second optical power meter to the second end of the optical fiber loop; determine the first optimal coupling position between the first end of the optical fiber loop and the first output end of the Y waveguide according to the optical power value of the beam emitted by the low-bias light source measured by the first optical power in the light source and the optical power value of the beam output from the second end of the optical fiber loop measured by the second optical power meter; Connect the second optical power meter to the first end of the optical fiber loop; determine the second optimal coupling position between the second end of the optical fiber loop and the second output end of the Y waveguide according to the optical power value of the beam emitted by the low-bias light source measured by the first optical power in the light source and the optical power value of the beam output from the first end of the optical fiber loop measured by the second optical power meter.

2. The fast and accurate polarization alignment method according to claim 1, wherein The first optimal coupling position and the second optimal coupling position satisfy: The difference between the optical power value of the beam output from the first end of the optical fiber loop and the optical power value of the beam output from the second end of the optical fiber loop is within the allowable range.

3. The rapid and accurate polarization alignment method according to claim 2, characterized in that In the fast and accurate polarization alignment device: A first pigtail head is provided at the end of the first end of the optical fiber loop, and a second pigtail head is provided at the end of the second end of the optical fiber loop; the first end of the optical fiber loop is connected to the second end of the coupling part or the input end of the extinction ratio tester through the first pigtail head; the second end of the optical fiber loop is connected to the second end of the coupling part or the input end of the extinction ratio tester through the second pigtail head.

4. The rapid and accurate polarization alignment method according to claim 2, wherein In the fast and accurate polarization alignment device: The light source includes a low-bias light source.

5. The fast and accurate polarization alignment method according to claim 3, wherein In the fast and accurate polarization alignment device: The light source further includes a coupler and a first optical power meter; The output end of the low-bias light source is connected to the first end of the coupler, and the output end of the coupler is used as the output end of the light source and is connected to the input end of the Y waveguide; The first optical power meter is connected to the second end of the coupler to measure the optical power value of the beam emitted by the low-bias light source; The device further includes a second optical power meter. When the first fiber optic pigtail head is connected to the second end of the coupling part, the input end of the second optical power meter is connected to the second fiber optic pigtail head to measure the power value of the light beam output from the second fiber optic pigtail head; when the second fiber optic pigtail head is connected to the second end of the coupling part, the input end of the second optical power meter is connected to the first fiber optic pigtail head to measure the power value of the light beam output from the first fiber optic pigtail head.

6. The rapid and accurate polarization alignment method according to any one of claims 1-5, characterized in that In the described fast and accurate polarization alignment device: Two coupling parts are arranged on the coupling table, and the positional relationship between the two coupling parts is adapted to the positional relationship between the first output end and the second output end of the Y waveguide.

Images