Preparation method of two-in and two-out mirror fiber ring and two-in and two-out mirror fiber ring

Abstract

The application relates to the technical field of fiber-optic gyroscopes, in particular to a preparation method of a two-in and two-out mirror image fiber-optic ring, which comprises the following steps: measuring two optical fibers with required lengths; marking the endpoints and the midpoints of the two optical fibers respectively; calculating a winding sequence change point and marking the same on the two optical fibers respectively; winding the two optical fibers on a fiber-optic ring skeleton in a mirror image symmetrical manner alternately by adopting a quadrupole symmetrical winding method until the winding sequence change point; changing the winding sequence of the two optical fibers; repeating steps d and e until the endpoint marks at the two ends of the optical fibers; and leading out four optical fiber tail fibers from the fiber-optic ring skeleton and fixing the same. According to the preparation method of the two-in and two-out mirror image fiber-optic ring, the two optical fiber rings have a mirror image relationship in space, so that the temperature phase errors generated by the two wound optical fiber rings are consistent, the phase errors caused by temperature changes in the Shupe effect can be compensated after joint signal processing, and the precision of the fiber-optic gyroscope is further improved.

Description

Technical Field

[0001] This invention relates to the field of fiber optic gyroscope technology, and in particular to a method for preparing a two-input two-output mirrored fiber optic ring and the two-input two-output mirrored fiber optic ring itself. Background Technology

[0002] An interferometric fiber optic gyroscope is a fiber optic ring interferometer based on the Sagnac effect. It describes the phase difference between two coherent beams propagating in opposite directions in the ring when the fiber rotates around the sensitive axis, which is proportional to the rotational angular velocity.

[0003] The fiber optic loop is the core component of an interferometric fiber optic gyroscope and serves as the sensing unit for rotation signal detection. Compared to other optical devices, its performance is significantly affected by temperature variations. During operation, the refractive index at corresponding points on the fiber optic loop changes with the ambient temperature over time. This causes two opposing light waves to pass through that point at different times (except at the midpoint of the fiber optic loop). Consequently, the phase changes of the two light waves after passing through the fiber optic loop due to temperature variations will also differ, effectively introducing an additional phase difference on top of the Sagnac phase shift. This effect is known as the Shupe effect. This effect causes the zero point of the fiber optic gyroscope to drift with temperature changes, severely affecting the full-temperature accuracy of the fiber optic gyroscope. It also leads to changes in the scaling factor, and instability in the scaling factor also affects the accuracy of the fiber optic gyroscope.

[0004] To ensure the temperature stability of fiber optic gyroscopes, the rate of temperature change must be the same at all symmetrical points relative to the midpoint of the fiber loop. The four-pole symmetric winding method is currently the most commonly used fiber optic winding method. Ideally, it can effectively reduce the impact of temperature changes on the non-reciprocity of the fiber, and the winding method is simple and the process is relatively mature. However, four-pole symmetric winding cannot completely eliminate the influence of the temperature gradient in the fiber loop, and the longer the fiber, the more pronounced the effect of this residual effect. Therefore, the non-reciprocal phase error caused by the Shupe effect limits further improvements in the accuracy of fiber optic gyroscopes. With the increasing demand for higher accuracy applications in recent years, solving this problem has become increasingly urgent. Summary of the Invention

[0005] The objective of this invention is to at least address the problem that the non-reciprocal phase error caused by temperature variations in the Shupe effect limits further improvements in the accuracy of fiber optic gyroscopes. This objective is achieved through the following technical solution:

[0006] The first aspect of this invention provides a method for fabricating a two-input, two-output mirrored fiber ring, comprising the following steps:

[0007] Step a: Measure two optical fibers of the required length and reserve sufficient length of fiber optic pigtails at both ends of the two optical fibers.

[0008] Step b: Mark the endpoints and midpoints of the two optical fibers respectively;

[0009] Step c: Calculate the points of change in winding sequence based on the fiber length and fiber ring skeleton size, and mark them on the two fibers respectively;

[0010] Step d: Use the four-pole symmetrical winding method to alternately wind the two optical fibers on the optical fiber ring skeleton in a mirror symmetrical manner until the winding order changes.

[0011] Step e: Change the winding order of the two optical fibers;

[0012] Step f: Repeat steps d and e until the endpoints of the fiber are marked.

[0013] Step g: Lead the four fiber optic pigtails out of the fiber optic ring frame and fix them in place;

[0014] Step h: Fix the wound two-in, two-out fiber optic ring.

[0015] According to the method for preparing a two-input, two-output mirrored fiber optic ring of the present invention, two optical fibers are wound into two fiber optic rings respectively. The two fiber optic rings are mirror images of each other in space and are integrated on a fiber optic ring skeleton. This ensures that the temperature phase error generated by the two wound fiber optic rings is consistent. After joint signal processing, the phase error caused by temperature change in the Shupe effect can be compensated, further improving the accuracy of the fiber optic gyroscope.

[0016] In addition, the fabrication method of the two-input two-output mirrored fiber ring according to the present invention may also have the following additional technical features:

[0017] In some embodiments of the present invention, the four-pole symmetrical winding method in step d includes the following steps:

[0018] Step 1: Take the midpoint of the optical fiber and attach it to the initial edge fixture on one side of the optical fiber ring frame. Wind the optical fiber on the side of the midpoint of the optical fiber clockwise or counterclockwise to the end edge fixture on the other side of the optical fiber ring frame to form the first optical fiber layer.

[0019] Step 2: The fiber on the other side of the midpoint of the fiber is wound in the opposite direction to that in Step 1 to the end edge tooling of the fiber ring skeleton to form the second fiber layer.

[0020] Step 3: Wind the optical fiber of the second optical fiber layer from the end edge fixture to the initial edge fixture in the opposite direction to Step 1 to form the third optical fiber layer;

[0021] Step 4: Wind the first fiber layer along the same direction as in Step 1 from the end edge fixture to the initial edge fixture to form the fourth fiber layer, completing a quadrupole symmetrical periodic winding.

[0022] In some embodiments of the present invention, step d, which involves alternately winding two optical fibers in a mirror-symmetrical manner using a four-pole symmetric winding method, includes the following steps:

[0023] Step 1: Place the midpoints of the two optical fibers on the edge fixtures on both sides of the optical fiber ring skeleton. The two optical fibers are wound on the optical fiber ring skeleton in opposite winding directions and according to Step 1 of the four-pole symmetric winding method to form the first optical fiber layer and the second optical fiber layer.

[0024] Step 2: Wind the two optical fibers onto the optical fiber ring skeleton one after the other according to Step 2 of the four-pole symmetric winding method to form the third optical fiber layer and the fourth optical fiber layer.

[0025] Step 3: Wind the two optical fibers onto the optical fiber ring skeleton one after the other according to step 3 of the four-pole symmetric winding method to form the fifth optical fiber layer and the sixth optical fiber layer.

[0026] Step 4: Wind the two optical fibers onto the optical fiber ring skeleton one after the other according to step 4 of the four-pole symmetric winding method to form the seventh optical fiber layer and the eighth optical fiber layer.

[0027] Step 5: Repeat steps 1 through 4.

[0028] In some embodiments of the present invention, the four-pole symmetrical winding method in step d includes the following steps:

[0029] Step 1: Attach the midpoint of the optical fiber to the initial edge fixture at the midpoint of the optical fiber ring frame, and wind the first side of the optical fiber to the first end edge fixture on one side of the optical fiber ring frame in a clockwise or counterclockwise winding direction.

[0030] Step 2: Wrap the second side of the optical fiber in the opposite winding direction to the second end edge tooling on the other side of the optical fiber ring skeleton;

[0031] Step 3: Wind the first side of the optical fiber from the first end edge fixture to the initial edge fixture in the same winding direction as in Step 1 but in the opposite winding direction to the initial edge fixture.

[0032] Step 4: The second side of the optical fiber is wound from the second end edge fixture to the initial edge fixture in the same winding direction as in Step 1 but in the opposite winding direction, to the initial edge fixture, completing a four-pole symmetrical periodic winding.

[0033] In some embodiments of the present invention, step d, which involves alternately winding two optical fibers in a mirror-symmetrical manner using a four-pole symmetric winding method, includes the following steps:

[0034] Step 1: Following the four-pole symmetric winding method, the two optical fibers are wound onto the optical fiber ring skeleton in opposite winding directions to form the first optical fiber layer of the two half-regions respectively.

[0035] Step 2: Wind the two optical fibers onto the optical fiber ring skeleton according to the four-pole symmetric winding method in step 2, forming the second optical fiber layer of the two half-regions respectively;

[0036] Step 3: Wind the two optical fibers onto the optical fiber ring skeleton according to step 3 of the four-pole symmetric winding method to form the third optical fiber layer of the two half-regions respectively.

[0037] Step 4: Wind the two optical fibers onto the optical fiber ring skeleton according to step 4 of the four-pole symmetric winding method to form the fourth optical fiber layer of the two half-regions respectively.

[0038] Step 5: Repeat steps 1 through 4.

[0039] In some embodiments of the present invention, step d, which involves alternately winding two optical fibers in a mirror-symmetrical manner using a four-pole symmetric winding method, includes the following steps:

[0040] Step 1: Following the four-pole symmetric winding method, the two optical fibers are wound onto the optical fiber ring skeleton in opposite winding directions to form the first optical fiber layer of the two half-regions respectively.

[0041] Step 2: Wind the two optical fibers onto the optical fiber ring skeleton according to the four-pole symmetric winding method in step 2, forming the second optical fiber layer of the two half-regions respectively;

[0042] Step 3: Wind the two optical fibers onto the optical fiber ring skeleton according to step 3 of the four-pole symmetric winding method to form the third optical fiber layer of the two half-regions respectively.

[0043] Step 4: Wind the two optical fibers onto the optical fiber ring skeleton according to step 4 of the four-pole symmetric winding method to form the fourth optical fiber layer of the two half-regions respectively.

[0044] Step 5: Swap the winding directions of the two optical fibers and continue with steps 1 to 4 according to the swapped winding directions.

[0045] Step Six: Repeat steps one through five.

[0046] In some embodiments of the present invention, the winding sequence changes when the number of layers of the optical fiber reaches n*8 layers, where n is an integer and n≥1.

[0047] In some embodiments of the present invention, fiber curing adhesive is applied between the layers of the fiber winding.

[0048] In some embodiments of the present invention, the method of fixing in step h is adhesive impregnation.

[0049] A second aspect of the present invention provides a two-input two-output mirrored fiber optic ring, which is prepared by the above-described method for preparing a two-input two-output fiber optic ring. Attached Figure Description

[0050] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0051] Figure 1 The first winding method of the preparation method of the two-input two-output mirrored fiber optic ring according to an embodiment of the present invention is illustrated schematically;

[0052] Figure 2 The second winding method of the preparation method of the two-input two-output mirrored fiber optic ring according to an embodiment of the present invention is illustrated schematically;

[0053] Figure 3 The diagram schematically illustrates a third winding method for preparing a two-input, two-output mirrored fiber optic ring according to an embodiment of the present invention.

[0054] Appendix Figure 4 The diagram shows experimental data of the shuttle temperature compensation according to an embodiment of the present invention;

[0055] Appendix Figure 5 A comparison chart of Allan variance analysis according to an embodiment of the present invention is shown.

[0056] The attached figures are labeled as follows:

[0057] 10 is the fiber optic ring skeleton, and 11 is the midpoint of the skeleton;

[0058] 20 is an optical fiber, 21 is the first optical fiber, and 22 is the second optical fiber;

[0059] 31 is the midpoint of the first optical fiber, and 32 is the midpoint of the second optical fiber. Detailed Implementation

[0060] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0061] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0062] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0063] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0064] like Figures 1 to 3 As shown, according to an embodiment of the present invention, a method for fabricating a two-input, two-output mirrored fiber optic ring is proposed, comprising the following steps:

[0065] Step a: Measure two optical fibers 20 of the required length, and reserve sufficient length of optical fiber pigtails at both ends of the two optical fibers 20 respectively.

[0066] Step b: Mark the endpoints and midpoints of the two optical fibers 20 respectively;

[0067] Step c: Calculate the points of change in winding sequence based on the length of fiber 20 and the size of fiber ring frame 10, and mark them on the two fibers 20 respectively;

[0068] Step d: Using the four-pole symmetrical winding method, the two optical fibers 20 are alternately wound on the optical fiber ring skeleton 10 in a mirror symmetrical manner until the winding sequence changes.

[0069] Step e: Change the winding order of the two optical fibers 20;

[0070] Step f: Repeat steps d and e until the endpoints of fiber 20 are marked.

[0071] Step g: Lead out the four fiber optic pigtails from the fiber optic ring frame 10 and fix them in place;

[0072] Step h: Fix the wound two-in, two-out fiber optic ring.

[0073] According to the method for preparing a two-input, two-output mirrored fiber optic ring of the present invention, two optical fibers 20 are wound into two fiber optic rings respectively. The two fiber optic rings are mirror images in space and are integrated on a fiber optic ring skeleton 10. This ensures that the temperature phase error generated by the two wound fiber optic rings is consistent. After joint signal processing, the phase error caused by temperature change in the Shupe effect can be compensated, further improving the accuracy of the fiber optic gyroscope.

[0074] It is understandable that the four-pole symmetrical winding method in step d includes the following steps:

[0075] Step 1: Take the midpoint of fiber 20 and attach it to the initial edge fixture on one side of the fiber ring frame 10. Wind the fiber 20 on the side of the midpoint of fiber 20 clockwise or counterclockwise to the end edge fixture on the other side of the fiber ring frame 10 to form the first fiber layer.

[0076] Step 2: The fiber 20 on the other side of the midpoint of the fiber 20 is wound in the opposite direction to that in Step 1 to the end edge tooling of the fiber ring skeleton 10 to form the second fiber layer.

[0077] Step 3: Wind the fiber 20 of the second fiber layer from the end edge fixture to the initial edge fixture in the opposite direction to Step 1 to form the third fiber layer;

[0078] Step 4: Wind the first fiber layer 20 from the end edge tooling to the initial edge tooling in the same direction as in Step 1 to form the fourth fiber layer, completing a quadrupole symmetrical periodic winding.

[0079] In some implementations, step d involves alternately winding the two optical fibers 20 in a mirror-symmetrical manner using a four-pole symmetric winding method, including the following steps:

[0080] Step 1: Place the midpoints of the two optical fibers 20 onto the edge fixtures on both sides of the optical fiber ring frame 10. The two optical fibers 20 are wound onto the optical fiber ring frame 10 in opposite winding directions and according to Step 1 of the four-pole symmetrical winding method to form the first optical fiber layer and the second optical fiber layer.

[0081] Step 2: The two optical fibers 20 are wound onto the optical fiber ring frame 10 in step 2 of the four-pole symmetric winding method to form the third optical fiber layer and the fourth optical fiber layer.

[0082] Step 3: Wind the two optical fibers 20 onto the optical fiber ring frame 10 in step 3 of the four-pole symmetric winding method to form the fifth optical fiber layer and the sixth optical fiber layer.

[0083] Step 4: Wind the two optical fibers 20 onto the optical fiber ring frame 10 in step 4 of the four-pole symmetric winding method to form the seventh optical fiber layer and the eighth optical fiber layer.

[0084] Step 5: Repeat steps 1 through 4.

[0085] It is understandable that the four-pole symmetrical winding method in step d includes the following steps:

[0086] Step 1: Attach the midpoint of the optical fiber 20 to the initial edge fixture at the midpoint of the optical fiber ring frame 10, and wind the first side of the optical fiber 20 to the first end edge fixture on one side of the optical fiber ring frame 10 in a clockwise or counterclockwise winding direction.

[0087] Step 2: Wrap the second side of the optical fiber 20 in the opposite winding direction to the second end edge tooling on the other side of the optical fiber ring skeleton 10;

[0088] Step 3: Wind the first side of the optical fiber 20 from the first end edge fixture to the initial edge fixture in the same winding direction as in Step 1 but in the opposite winding direction to the initial edge fixture.

[0089] Step 4: The second side of the optical fiber 20 is wound from the second end edge fixture to the initial edge fixture in the same winding direction as in Step 1 but in the opposite winding direction, to the initial edge fixture, completing a four-pole symmetrical periodic winding.

[0090] In some implementations, step d involves alternately winding the two optical fibers 20 in a mirror-symmetrical manner using a four-pole symmetric winding method, including the following steps:

[0091] Step 1: The two optical fibers 20 are wound onto the optical fiber ring skeleton 10 in opposite winding directions and winding methods according to Step 1 of the four-pole symmetric winding method, forming the first optical fiber layer of the two half-regions respectively.

[0092] Step 2: Wind the two optical fibers 20 onto the optical fiber ring frame 10 according to step 2 of the four-pole symmetrical winding method to form the second optical fiber layer of the two half-regions respectively.

[0093] Step 3: Wind the two optical fibers 20 onto the optical fiber ring skeleton 10 according to step 3 of the four-pole symmetrical winding method to form the third optical fiber layer of the two half-regions respectively.

[0094] Step 4: Wind the two optical fibers 20 onto the optical fiber ring skeleton 10 according to step 4 of the four-pole symmetric winding method to form the fourth optical fiber layer of the two half-regions respectively.

[0095] Step 5: Repeat steps 1 through 4.

[0096] In some implementations, step d involves alternately winding the two optical fibers 20 in a mirror-symmetrical manner using a four-pole symmetric winding method, including the following steps:

[0097] Step 1: The two optical fibers 20 are wound onto the optical fiber ring skeleton 10 in opposite winding directions and winding methods according to Step 1 of the four-pole symmetric winding method, forming the first optical fiber layer of the two half-regions respectively.

[0098] Step 2: Wind the two optical fibers 20 onto the optical fiber ring frame 10 according to step 2 of the four-pole symmetrical winding method to form the second optical fiber layer of the two half-regions respectively.

[0099] Step 3: Wind the two optical fibers 20 onto the optical fiber ring skeleton 10 according to step 3 of the four-pole symmetrical winding method to form the third optical fiber layer of the two half-regions respectively.

[0100] Step 4: Wind the two optical fibers 20 onto the optical fiber ring skeleton 10 according to step 4 of the four-pole symmetric winding method to form the fourth optical fiber layer of the two half-regions respectively.

[0101] Step 5: Swap the winding directions of the two optical fibers 20, and continue to complete steps 1 to 4 according to the swapped winding directions.

[0102] Step Six: Repeat steps one through five.

[0103] Specifically, the winding sequence changes when the number of optical fiber winding layers reaches n*8 layers, where n is an integer and n≥1.

[0104] Specifically, fiber optic adhesive is applied between the layers of the fiber optic cable 20.

[0105] Specifically, the method for fixing in step h is adhesive impregnation.

[0106] Specifically, such as Figures 1 to 3 As shown in the figure, the circles without cross-sections represent the first optical fiber 21, the circles with cross-sections represent the second optical fiber 22, the circles with solid circles represent optical fiber 20 wound in direction A, the circles with hollow circles represent optical fiber 20 wound in direction B, and the arrows indicate the direction of optical fiber winding.

[0107] like Figure 1 As shown, the first winding method of the two-input two-output mirrored fiber ring preparation method of the embodiment is to measure two optical fibers 20 of the required length, leave sufficient length of optical fiber tails at both ends, and mark them as the first optical fiber 21 and the second optical fiber 22.

[0108] (1) Mark the two ends and the midpoint of the first optical fiber 21 and the second optical fiber 22 according to the calculation. Divide the first optical fiber 21 into two segments 1A and 1B with the midpoint as the boundary, and divide the second optical fiber 22 into two segments 2A and 2B. Calculate and mark the winding sequence change points according to the length of the optical fiber 20 and the skeleton size.

[0109] (2) Take the first fiber 21 and place the midpoint 31 of the first fiber 21 close to the left edge of the inner wall of the fiber ring frame 10. Wrap the 1A segment tightly on the fiber ring frame 10 in the A winding direction until the first fiber 21 is close to the right edge of the fiber ring frame 10, and complete the winding of the first fiber layer.

[0110] (3) Take the midpoint 32 of the second optical fiber 22 and place it tightly against the right edge of the inner wall of the optical fiber ring frame 10. Wrap the 2B segment tightly around the optical fiber ring frame 10 in the B winding direction until the second optical fiber 22 is tightly against the left edge of the optical fiber ring frame 10, thus completing the winding of the second optical fiber layer.

[0111] (4) Wrap segment 1B tightly around the fiber ring frame 10 in the B winding direction until the first fiber 21 is close to the right edge of the fiber ring frame 10, thus completing the winding of the third fiber layer; wrap segment 2A tightly around the fiber ring frame 10 in the A winding direction until the second fiber 22 is close to the left edge of the fiber ring frame 10, thus completing the winding of the fourth fiber layer.

[0112] (5) Wrap segment 1B tightly around the fiber ring frame 10 from the right edge in the B winding direction until the first fiber 21 is close to the left edge of the fiber ring frame 10, thus completing the winding of the fifth fiber layer; wrap segment 2A tightly around the fiber ring frame 10 from the left edge in the A winding direction until the second fiber 22 is close to the right edge of the fiber ring frame 10, thus completing the winding of the sixth fiber layer.

[0113] (6) Wrap segment 1A tightly around the fiber ring frame 10 from the right edge in the A winding direction until the first fiber 21 is close to the left edge of the fiber ring frame 10, thus completing the winding of the seventh fiber layer; wrap segment 2B tightly around the fiber ring frame 10 from the left edge in the B winding direction until the second fiber 22 is close to the right edge of the fiber ring frame 10, thus completing the winding of the eighth fiber layer.

[0114] (7) Repeat steps (2) to (6) of Method 1 above with the first optical fiber 21 and the second optical fiber 22 until the winding order changes.

[0115] (8) Change the winding order and wind the second fiber 22 and the first fiber 21 onto the fiber ring skeleton 10 layer by layer according to steps (2) to (6) of the above method one, until the end mark.

[0116] (9) Lead out the four fiber pigtails from the fiber ring frame 10 and fix them.

[0117] like Figure 2 As shown, this is the second winding method of the two-input two-output mirrored fiber ring preparation method of the embodiment. Two optical fibers of the required length are measured, and sufficient length of fiber tails are left at both ends, and they are marked as the first optical fiber 21 and the second optical fiber 22.

[0118] (1) Mark the two ends and the midpoint of the first optical fiber 21 and the second optical fiber 22 according to the calculation. Divide the first optical fiber 21 into two segments 1A and 1B with the midpoint as the boundary, and divide the second optical fiber 22 into two segments 2A and 2B. Calculate and mark the winding sequence change points according to the length of the optical fiber 20 and the skeleton size.

[0119] (2) Take the first fiber 31 of the first fiber 21 and tightly attach it to the midpoint 11 of the skeleton. Wrap the 1A segment of the first fiber 21 tightly around the fiber ring skeleton 10 from the midpoint 11 of the skeleton in the A winding direction until the right edge of the fiber ring skeleton 10 is reached, forming the right half region. Take the second fiber 32 of the second fiber 22 and tightly attach it to the midpoint 11 of the skeleton. Wrap the 2B segment of the second fiber 22 tightly around the fiber ring skeleton 10 in the B winding direction until the left edge of the fiber ring skeleton 10 is reached, forming the left half region, thus completing the winding of the first fiber layer.

[0120] (3) Wrap the 1B segment of the first optical fiber 21 tightly around the fiber ring frame 10 from the midpoint 11 of the frame in the B winding direction until the left edge of the fiber ring frame 10, and then wrap it back from the left edge to the midpoint 11 of the frame; wrap the 2A segment of the second optical fiber 22 tightly around the fiber ring frame 10 from the midpoint 11 of the frame in the A winding direction until the right edge of the fiber ring frame 10, and then wrap it back from the right edge to the midpoint 11 of the frame, thus completing the winding of the second and third optical fiber layers.

[0121] (4) Wrap the 1A segment of the first optical fiber 21 tightly around the optical fiber ring skeleton 10 from the right edge in the A winding direction until the midpoint 11 of the skeleton; wrap the 2B segment of the second optical fiber 22 tightly around the optical fiber ring skeleton 10 from the left edge in the B winding direction until the midpoint 11 of the skeleton, thus completing the winding of the fourth optical fiber layer.

[0122] (5) Repeat steps (2) to (4) of method two above with the first optical fiber 21 and the second optical fiber 22 in turn until the winding order changes.

[0123] (6) Change the winding order and repeat steps (2) to (5) of method two to wind the second fiber 22 and the first fiber 21 layer by layer onto the fiber ring skeleton 10 until the end mark.

[0124] (7) Lead out the four fiber pigtails from the fiber ring frame 10 and fix them.

[0125] like Figure 3 As shown, this is the third winding method of the two-input two-output mirror fiber ring preparation method of the embodiment. Two optical fibers 20 of the required length are measured, and sufficient length of optical fiber pigtails are left at both ends, and they are marked as the first optical fiber 21 and the second optical fiber 22.

[0126] (1) Mark the two ends and the midpoint of the first optical fiber 21 and the second optical fiber 22 according to the calculation. Divide the first optical fiber 21 into two segments 1A and 1B with the midpoint as the boundary, and divide the second optical fiber 22 into two segments 2A and 2B. Calculate and mark the winding sequence change points according to the length of the optical fiber 20 and the skeleton size.

[0127] (2) Take the first fiber 31 of the first fiber 21 and tightly attach it to the midpoint 11 of the skeleton. Wrap the 1A segment of the first fiber 21 tightly around the fiber ring skeleton 10 from the midpoint 11 of the skeleton in the A winding direction until the right edge of the fiber ring skeleton 10 is reached, forming the right half region. Take the second fiber 32 of the second fiber 22 and tightly attach it to the midpoint 11 of the skeleton. Wrap the 2B segment of the second fiber 22 tightly around the fiber ring skeleton 10 in the B winding direction until the left edge of the fiber ring skeleton 10 is reached, forming the left half region, thus completing the winding of the first fiber layer.

[0128] (3) Wrap the 1B segment of the first optical fiber 21 tightly around the fiber ring frame 10 from the midpoint 11 of the frame in the B winding direction until the left edge of the fiber ring frame 10, and then wrap it back from the left edge to the midpoint 11 of the frame; wrap the 2A segment of the second optical fiber 22 tightly around the fiber ring frame 10 from the midpoint 11 of the frame in the A winding direction until the right edge of the fiber ring frame 10, and then wrap it back from the right edge to the midpoint 11 of the frame, thus completing the winding of the second and third optical fiber layers.

[0129] (4) Wrap the 1A segment of the first optical fiber 21 tightly around the optical fiber ring skeleton 10 from the right edge in the A winding direction until the midpoint 11 of the skeleton; wrap the 2B segment of the second optical fiber 22 tightly around the optical fiber ring skeleton 10 from the left edge in the B winding direction until the midpoint 11 of the skeleton, thus completing the winding of the fourth optical fiber layer.

[0130] (5) Take the 1A segment of the first optical fiber 21 and tightly wrap it around the fiber ring frame 10 from the midpoint 11 of the frame in the A winding direction until the left edge of the fiber ring frame 10; take the second optical fiber 22 and tightly attach the second optical fiber 22 to the midpoint 32 of the frame 11; take the 2B segment of the second optical fiber 22 and tightly wrap it around the fiber ring frame 10 in the B winding direction until the right edge of the fiber ring frame 10, thus completing the winding of the fifth optical fiber layer.

[0131] (6) Wrap the 1B segment of the first optical fiber 21 tightly around the fiber ring frame 10 from the midpoint 11 of the frame in the B winding direction until the right edge of the fiber ring frame 10, and then wrap it back from the right edge to the midpoint 11 of the frame; wrap the 2A segment of the second optical fiber 22 tightly around the fiber ring frame 10 from the midpoint 11 of the frame in the A winding direction until the left edge of the fiber ring frame 10, and then wrap it back from the left edge to the midpoint 11 of the frame, thus completing the winding of the sixth and seventh fiber layers.

[0132] (7) Wrap the 1A segment of the first optical fiber 21 tightly around the optical fiber ring skeleton 10 from the left edge in the A winding direction until the midpoint 11 of the skeleton; wrap the 2B segment of the second optical fiber 22 tightly around the optical fiber ring skeleton 10 from the right edge in the B winding direction until the midpoint 11 of the skeleton, thus completing the winding of the eighth optical fiber layer.

[0133] (8) Repeat steps (2) to (7) of method three above with the first optical fiber 21 and the second optical fiber 22 until the winding order change point.

[0134] (9) Change the winding order and repeat steps (2) to (8) of method three to wind the second fiber 22 and the first fiber 21 onto the fiber ring skeleton 10 layer by layer until the end mark.

[0135] (10) Lead out the four fiber pigtails from the fiber ring frame 10 and fix them.

[0136] The present invention also proposes a two-input two-output mirrored fiber optic ring, which is prepared by the above-described method for preparing a two-input two-output fiber optic ring.

[0137] The following data were measured using a two-input, two-output mirrored fiber optic ring connected to a dual-polarization optical path according to an embodiment of the present invention:

[0138] The data obtained here shows the output changes during ambient temperature variations. The testing of the two-input, two-output mirrored fiber optic ring followed the "Fiber Optic Gyroscope Test Method" and also referenced IEEE standards for key chassis performance parameters such as zero-bias stability and random walk coefficients. This resulted in a set of test coefficients capable of performing various performance tests, including temperature testing. The composition is as follows... Figure 4 , Figure 5 As shown.

[0139] in, Figure 4 FOG1 and FOG2 are the output results before compensation, and SUM is the output result after compensation. Figure 4 As can be seen from the data, the zero-bias stability value is stable and the compensation effect is good.

[0140] in, Figure 5 FOG1 and FOG2 are parameters measured at the ports of the two optical fibers, and SUM is a parameter obtained using joint signal processing. Figure 5 As can be seen, the embodiments of the present invention can compensate for the phase error caused by temperature changes in the Shupe effect, thereby further improving the accuracy of the fiber optic gyroscope.

[0141] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for fabricating a two-input, two-output mirrored fiber optic ring, characterized in that, Includes the following steps: Step a: Measure two optical fibers of the required length and reserve sufficient length of fiber optic pigtails at both ends of the two optical fibers. Step b: Mark the endpoints and midpoints of the two optical fibers respectively; Step c: Calculate the points of change in winding sequence based on the fiber length and fiber ring skeleton size, and mark them on the two fibers respectively; Step d: The two optical fibers are alternately wound on the optical fiber ring skeleton in a mirror-symmetric manner using the four-pole symmetric winding method until the winding sequence changes. The winding sequence changes when the number of layers of optical fiber winding reaches n*8 layers, where n is an integer and n≥1. Step e: Change the winding order of the two optical fibers; Step f: Repeat steps d and e until the endpoints of the fiber are marked. Step g: Lead the four fiber optic pigtails out of the fiber optic ring frame and fix them in place; Step h: Fix the wound two-in, two-out fiber optic ring; The four-pole symmetrical winding method in step d includes the following steps: Step 1: Take the midpoint of the optical fiber and attach it to the initial edge fixture on one side of the optical fiber ring frame. Wind the optical fiber on the side of the midpoint of the optical fiber clockwise or counterclockwise to the end edge fixture on the other side of the optical fiber ring frame to form the first optical fiber layer. Step 2: The fiber on the other side of the midpoint of the fiber is wound in the opposite direction to that in Step 1 to the end edge tooling of the fiber ring skeleton to form the second fiber layer. Step 3: Wind the optical fiber of the second optical fiber layer from the end edge fixture to the initial edge fixture in the opposite direction to Step 1 to form the third optical fiber layer; Step 4: Wind the first fiber layer along the same direction as in Step 1 from the end edge fixture to the initial edge fixture to form the fourth fiber layer, completing a quadrupole symmetrical periodic winding.

2. The method for fabricating a two-input, two-output mirrored fiber optic ring according to claim 1, characterized in that, Step d involves using a four-pole symmetrical winding method to alternately wind the two optical fibers in a mirror-symmetrical manner, including the following steps: Step 1: Place the midpoints of the two optical fibers on the edge fixtures on both sides of the optical fiber ring skeleton. The two optical fibers are wound on the optical fiber ring skeleton in opposite winding directions and according to Step 1 of the four-pole symmetric winding method to form the first optical fiber layer and the second optical fiber layer. Step 2: Wind the two optical fibers onto the optical fiber ring skeleton one after the other according to Step 2 of the four-pole symmetric winding method to form the third optical fiber layer and the fourth optical fiber layer. Step 3: Wind the two optical fibers onto the optical fiber ring skeleton one after the other according to step 3 of the four-pole symmetric winding method to form the fifth optical fiber layer and the sixth optical fiber layer. Step 4: Wind the two optical fibers onto the optical fiber ring skeleton one after the other according to step 4 of the four-pole symmetric winding method to form the seventh optical fiber layer and the eighth optical fiber layer. Step 5: Repeat steps 1 through 4.

3. The method for fabricating a two-input, two-output mirrored fiber optic ring according to claim 1, characterized in that, The four-pole symmetrical winding method in step d includes the following steps: Step 1: Attach the midpoint of the optical fiber to the initial edge fixture at the midpoint of the optical fiber ring frame, and wind the first side of the optical fiber to the first end edge fixture on one side of the optical fiber ring frame in a clockwise or counterclockwise winding direction. Step 2: Wrap the second side of the optical fiber in the opposite winding direction to the second end edge tooling on the other side of the optical fiber ring skeleton; Step 3: Wind the first side of the optical fiber from the first end edge fixture to the initial edge fixture in the same winding direction as in Step 1 but in the opposite winding direction to the initial edge fixture. Step 4: The second side of the optical fiber is wound from the second end edge fixture to the initial edge fixture in the same winding direction as in Step 1 but in the opposite winding direction, to the initial edge fixture, completing a four-pole symmetrical periodic winding.

4. The method for fabricating a two-input, two-output mirrored fiber optic ring according to claim 3, characterized in that, Step d involves using a four-pole symmetrical winding method to alternately wind the two optical fibers in a mirror-symmetrical manner, including the following steps: Step 1: Following the four-pole symmetric winding method, the two optical fibers are wound onto the optical fiber ring skeleton in opposite winding directions to form the first optical fiber layer of the two half-regions respectively. Step 2: Wind the two optical fibers onto the optical fiber ring skeleton according to the four-pole symmetric winding method in step 2, forming the second optical fiber layer of the two half-regions respectively; Step 3: Wind the two optical fibers onto the optical fiber ring skeleton according to step 3 of the four-pole symmetric winding method to form the third optical fiber layer of the two half-regions respectively. Step 4: Wind the two optical fibers onto the optical fiber ring skeleton according to step 4 of the four-pole symmetric winding method to form the fourth optical fiber layer of the two half-regions respectively. Step 5: Repeat steps 1 through 4.

5. The method for fabricating a two-input, two-output mirrored fiber optic ring according to claim 3, characterized in that, Step d involves using a four-pole symmetrical winding method to alternately wind the two optical fibers in a mirror-symmetrical manner, including the following steps: Step 1: Following the four-pole symmetric winding method, the two optical fibers are wound onto the optical fiber ring skeleton in opposite winding directions to form the first optical fiber layer of the two half-regions respectively. Step 2: Wind the two optical fibers onto the optical fiber ring skeleton according to the four-pole symmetric winding method in step 2, forming the second optical fiber layer of the two half-regions respectively; Step 3: Wind the two optical fibers onto the optical fiber ring skeleton according to step 3 of the four-pole symmetric winding method to form the third optical fiber layer of the two half-regions respectively. Step 4: Wind the two optical fibers onto the optical fiber ring skeleton according to step 4 of the four-pole symmetric winding method to form the fourth optical fiber layer of the two half-regions respectively. Step 5: Swap the winding directions of the two optical fibers and continue with steps 1 to 4 according to the swapped winding directions. Step Six: Repeat steps one through five.

6. The method for fabricating a two-input, two-output mirrored fiber optic ring according to claim 1, characterized in that, Optical fiber curing adhesive is applied between the layers of the optical fiber winding.

7. The method for fabricating a two-input, two-output mirrored fiber optic ring according to claim 1, characterized in that, The method of fixation in step h is adhesive impregnation.

8. A two-input, two-output mirrored fiber optic ring, characterized in that, The two-input two-output mirrored fiber optic ring is prepared by the preparation method of the two-input two-output mirrored fiber optic ring according to any one of claims 1-7.

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