Optical fiber delay device and delay measurement device

Abstract

The application belongs to the technical field of optical fiber delay, and discloses an optical fiber delay device and a delay measurement device, wherein the optical fiber delay device comprises a support, a delay optical fiber, a first winding section and a second winding section connected to the first winding section, the first winding section is wound on the support around an axis and forms a first optical fiber ring, a plurality of first optical fiber rings are nested to form a plurality of first ring groups, the second winding section is wound on the support around the axis and forms a second optical fiber ring, a plurality of second optical fiber rings are nested to form a plurality of second ring groups, the second ring groups and the first ring groups are nested with each other and are alternately arranged, one end of the first winding section away from the second winding section is an input end, one end of the second winding section away from the first winding section is an output end, the input end and the output end both extend out of each first ring group and each second ring group, a first collimating lens is connected to the input end, and a second collimating lens is connected to the output end. The application can solve the technical problem that the end of the delay optical fiber is easily covered.

Description

Technical Field

[0001] This application belongs to the field of optical fiber delay technology, specifically relating to an optical fiber delay device and a delay measurement device. Background Technology

[0002] Fiber optic delay devices can control the transmission time of optical signals along different paths, enabling multiple nodes to receive signals synchronously. A typical fiber optic delay device consists of a fiber delay loop formed by winding delay fibers. The two ends of the delay fibers are located on the inner and outer sides of the delay loop radially. The end of the delay fiber located on the inner side of the delay loop is easily covered by the outer part of the delay loop, making it difficult to connect one end of the delay loop to other devices. Utility Model Content

[0003] The purpose of this application is to provide an optical fiber delay device and a delay measurement device to solve the technical problem that the ends of the delay optical fiber are easily covered in the prior art.

[0004] To achieve the above objectives, an embodiment of the first aspect of this application provides an optical fiber delay device, comprising: a support member; a delay optical fiber, including a first winding segment and a second winding segment connected to the first winding segment, the first winding segment being wound around an axis on the support member to form a first optical fiber loop, and multiple first optical fiber loops being nested radially to form multiple first loop groups; the second winding segment being wound around an axis on the support member to form a second optical fiber loop, and multiple second optical fibers being nested radially to form multiple second loop groups, the second loop groups and the first loop groups being nested radially and alternately arranged, the end of the first winding segment away from the second winding segment being an input end, the end of the second winding segment away from the first winding segment being an output end, and both the input end and the output end extending beyond each first loop group and each second loop group; a first collimating lens connected to the input end; and a second collimating lens connected to the output end.

[0005] In some embodiments, the fiber delay device further includes a protective box; a support member and a portion of the delay fiber are fixed inside the protective box; and a first collimating lens and a second collimating lens are located outside the protective box.

[0006] In some embodiments, the fiber delay device further includes multiple output fibers and a first fiber coupler. The first fiber coupler is fixed inside a protective box, one end of the first fiber coupler is connected to the output end, and the other end of the first fiber coupler is connected to multiple output fibers. Multiple second collimating lenses are provided, and the multiple second collimating lenses are respectively connected to the corresponding output fibers.

[0007] In some embodiments, the fiber optic delay device further includes a first sleeve connected to and located outside the protective box, with the input end passing through the first sleeve; and / or, the fiber optic delay device further includes a second sleeve connected to and located outside the protective box, with the output fiber passing through the second sleeve.

[0008] In some embodiments, the difference in length between the two output optical fibers is less than or equal to 0.5 mm.

[0009] In some embodiments, the protective box includes a mounting wall, and one end of a support member along the axis is fixed to the mounting wall; at one end of the support member along the axis near the mounting wall, a first winding segment and a second winding segment respectively contact the support member and extend to the mounting wall, and the first winding segment and the second winding segment are fixed to the mounting wall.

[0010] In some embodiments, the support includes a support column and two limiting plates. The length direction of the support column is parallel to the axis. The two limiting plates are respectively connected to the two ends of the support column along its own length direction. The two limiting plates are used to block the movement of the first fiber ring and the second fiber ring.

[0011] In some embodiments, the protective box is a titanium alloy component, the support component is a titanium alloy component; and / or, the delay fiber is an ultraviolet radiation resistant fiber.

[0012] In some embodiments, a first fixing adhesive is provided on the outer surface of the time-delay fiber, and the time-delay fiber is bonded to the support member by the first fixing adhesive; a plurality of first fiber rings and a plurality of second fiber rings are bonded together by the first fixing adhesive.

[0013] An embodiment of the second aspect of this application also provides a delay measurement device for measuring the fiber optic delay device of any one of the embodiments of the first aspect. The delay measurement device includes a light source, a connecting fiber, a second fiber coupler, and a reference fiber connected in sequence. The second fiber coupler is used to connect the connecting fiber to a second collimating lens. The delay measurement device also includes an oscilloscope and two photoelectric converters. The photoelectric converters are electrically connected to the oscilloscope. The two photoelectric converters are used to convert the optical signal output from the first collimating lens and the optical signal output from the reference fiber into electrical signals and transmit them to the oscilloscope. The oscilloscope is used to measure the phase delay between the electrical signals transmitted by the two photoelectric converters.

[0014] The beneficial effects of the fiber optic delay device and delay measurement device provided in this application are as follows: Dividing the delay fiber into a first winding segment and a second winding segment with a relatively long length, and alternating between the first and second winding segments, prevents the output end from being covered during the winding of the first winding segment and the input end from being covered during the winding of the second winding segment. This allows the input and output ends to extend stably beyond the first and second ring groups, facilitating the connection of the input and output ends to the first and second collimating lenses. Since the first ring group includes multiple first fiber rings and the second ring group includes multiple second fiber rings, each winding process forms multiple first fiber rings or multiple second fiber rings, resulting in fewer winding operations and higher winding efficiency compared to forming only one first fiber ring or one second fiber ring each time. The use of the first and second collimating lenses converts the optical signal into a parallel beam for transmission, reducing signal attenuation. This application solves the technical problem of the ends of the delay fiber being easily covered. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of an optical fiber delay device provided in some embodiments of this application;

[0017] Figure 2 A schematic diagram of a time-delay fiber wound on a support member, provided for some embodiments of this application;

[0018] Figure 3 for Figure 2 Cross-sectional view (AA) of the intermediate-delay optical fiber and its support;

[0019] Figure 4 for Figure 3 Enlarged view of part A in the middle;

[0020] Figure 5 This is a schematic diagram of the structure of the protective box provided in some embodiments of this application;

[0021] Figure 6 This is a schematic diagram of the internal structure of the protective box provided in some embodiments of this application;

[0022] Figure 7 Flowcharts illustrating the fabrication process of the fiber optic delay device provided in some embodiments of this application;

[0023] Figure 8This is a schematic diagram showing the connection between a delay measurement device and an optical fiber delay device provided in some embodiments of this application.

[0024] The following are the labeling elements in the figure:

[0025] 100. Fiber optic delay device;

[0026] 10. Support component; 11. Support column; 12. Limiting plate; 13. Axis; 14. Fixed end;

[0027] 20. Delay fiber; 21. First ring group; 211. First fiber ring; 22. Input end; 23. Second ring group; 231. Second fiber ring; 24. Output end;

[0028] 30. First collimating lens;

[0029] 40. Second collimating lens; 41. Output optical fiber;

[0030] 50. First casing;

[0031] 60. Second casing;

[0032] 70. First fiber optic coupler;

[0033] 80. Welded protective sleeve;

[0034] 90. Protective box; 91. Box body; 911. Wiring hole; 912. Threaded hole; 913. Mounting wall; 92. Box cover;

[0035] 200. Delay measurement device; 201. Light source; 202. Connecting optical fiber; 2021. First connecting optical fiber; 2022. Second connecting optical fiber; 203. Mode field adapter; 204. Second optical fiber coupler; 205. Reference optical fiber; 206. Oscilloscope; 207. Optoelectronic converter; 208. Optical fiber connector; 209. Adapter; 210. Ceramic ferrule. Detailed Implementation

[0036] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0037] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0038] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0040] An embodiment of the first aspect of this application provides an optical fiber delay device that can adjust the transmission time of an optical signal in devices such as remote sensing equipment and medical imaging equipment, so that the optical signal transmitted by the optical fiber delay device is synchronized with other signals.

[0041] Please refer to Figures 1 to 4 The fiber optic delay device 100 includes a support 10, a delay fiber 20, a first collimating lens 30, and a second collimating lens 40.

[0042] The delay fiber 20 includes a first winding segment and a second winding segment connected to the first winding segment. The first winding segment is wound around the axis 13 on the support member 10 to form a first fiber loop 211. Multiple first fiber loops 211 are nested radially to form multiple first ring groups 21. The second winding segment is wound around the axis 13 on the support member 10 to form a second fiber loop 231. Multiple second fiber loops 231 are nested radially to form multiple second ring groups 23. The second ring groups 23 and the first ring groups 21 are nested together radially and alternately arranged. The end of the first winding segment away from the second winding segment is the input end 22, and the end of the second winding segment away from the first winding segment is the output end 24. Both the input end 22 and the output end 24 extend beyond each first ring group 21 and each second ring group 23.

[0043] The first collimating lens 30 is connected to the input terminal 22. The second collimating lens 40 is connected to the output terminal 24.

[0044] The support member 10 is used to support the delay fiber 20. Optionally, the support member 10 may include a circular tube with axis 13 as the center line. The delay fiber 20 contacts the arc surface of the circular tube during winding, resulting in less wear, and the circular tube is also lighter. Optionally, the support member 10 may also include a circular rod, square tube, etc., with axis 13 as the center line.

[0045] The time-delay fiber 20 is used to extend the transmission time of optical signals. The time-delay fiber 20 is divided into two segments at a point, which are designated as the first winding segment and the second winding segment. The transmission time of the optical signal in the time-delay fiber 20 is positively correlated with the length of the time-delay fiber 20. Since the time-delay fiber 20 is relatively long, winding it around the support member 10 can reduce its volume.

[0046] The first winding segment is spirally wound onto the support member 10, with one turn of the first winding segment forming a first winding loop. A first fiber loop 211 includes multiple first winding loops arranged sequentially along the axis 13. Each first fiber loop 211 is a spiral coil extending along the axis 13. For example, when the first winding segment is wound on a circular tube, the first winding loops in the same first fiber loop 211 have the same size in any direction perpendicular to the axis 13.

[0047] After the first fiber optic loop 211 is formed by winding, the first winding segment is wound onto the first fiber optic loop 211 to form a second fiber optic loop 211. This means that the second fiber optic loop 211 and the first fiber optic loop 211 are radially nested. Multiple fiber optic loops 211 are radially nested together, and the size of the first fiber optic loop 211 gradually increases from the center to the outside in the radial direction. Radial direction refers to the extension direction of any straight line perpendicular to and intersecting axis 13.

[0048] Multiple first ring groups 21 are nested together radially. The multiple first fiber rings 211 in each first ring group 21 are formed by winding a continuous first winding segment. Two adjacent first ring groups 21 are formed by winding a continuous first winding segment.

[0049] The second winding segment is spirally wound onto the support member 10, with each turn of the second winding segment forming a second winding loop. A second fiber loop 231 comprises multiple second winding loops arranged sequentially along axis 13. Each second fiber loop 231 is a spiral coil extending along axis 13. For example, when the second winding segment is wound on a circular tube, the second winding loops in the same second fiber loop 231 have the same size in any direction perpendicular to axis 13.

[0050] After the first second fiber loop 231 is formed by winding, the second winding segment is wound on the first second fiber loop 231 to form the second second fiber loop 231. This means that the second second fiber loop 231 and the first second fiber loop 231 are nested radially. Multiple second fiber loops 231 are nested together radially, and the radial dimension of the second fiber loop 231 gradually increases from the center to the outside.

[0051] Multiple second ring groups 23 are nested together radially, and multiple second fiber rings 231 in each second ring group 23 are continuously arranged. The multiple second fiber rings 231 in each second ring group 23 are formed by winding a continuous second winding segment, and two adjacent second ring groups 23 are formed by winding a continuous second winding segment.

[0052] The second ring group 23 and the first ring group 21 are nested and alternately arranged, meaning the first winding segment and the second winding segment are wound alternately. The first winding segment can be wound to form multiple first ring groups 21, meaning the length of the first winding segment is relatively large, making it difficult for the first winding segment to be covered when the second winding segment is wound. The unwound portion of the first winding segment is located outside the first ring group 21 and the second ring group 23. The second winding segment can be wound to form multiple second ring groups 23, meaning the length of the second winding segment is relatively large, making it difficult for the second winding segment to be covered when the first winding segment is wound. The unwound portion of the second winding segment is located outside the first ring group 21 and the second ring group 23.

[0053] The first and second winding sections are made from the same delay fiber 20. Each delay fiber 20 has two ends: an input end 22 and an output end 24. The input end 22 is the end of the first winding section furthest from the second winding section, and the output end 24 is the end of the second winding section furthest from the first winding section. After winding, the unwound input end 22 and output end 24 are located outside each first ring group 21 and each second ring group 23.

[0054] The first collimating lens 30 can receive optical signals from outside the fiber optic delay device 100 and convert them into a parallel beam. The input end 22 of the delay fiber 20 can receive the optical signals transmitted by the first collimating lens 30. Optionally, the first collimating lens 30 can be an integrated collimating lens, which has a simpler structure and more stable optical performance. Optionally, the first collimating lens 30 can also be a combined collimating lens, which consists of a connector and a lens, making it convenient to assemble and disassemble the lens.

[0055] The second collimating lens 40 can receive the optical signal transmitted by the delay fiber 20 and convert it into a parallel beam before transmitting it to a device outside the fiber optic delay device 100. Optionally, the second collimating lens 40 can be an integrated collimating lens, which has a simpler structure and more stable optical performance. Alternatively, the second collimating lens 40 can also be a modular collimating lens, which facilitates lens replacement.

[0056] In use, the first collimating lens 30 is connected to the signal input device, and the second collimating lens 40 is connected to the signal receiving device. The signal input device transmits the optical signal to the first collimating lens 30, which converts the optical signal into a parallel beam and transmits it to the delay fiber 20. The delay fiber 20 then transmits the optical signal to the second collimating lens 40. Because the delay fiber 20 is relatively long, the optical signal travels for a longer time within it. The second collimating lens 40 converts the optical signal into a parallel beam and transmits it to the signal receiving device.

[0057] The beneficial effects of this embodiment are as follows: dividing the delay fiber 20 into a first winding segment and a second winding segment with a larger length, and winding the first and second winding segments alternately, can prevent the output end 24 from being covered during the winding of the first winding segment, and can prevent the input end 22 from being covered during the winding of the second winding segment. This allows the input end 22 and the output end 24 to extend stably outside the first ring group 21 and the second ring group 23, making it easy to connect the input end 22 and the output end 24 to the first collimating lens 30 and the second collimating lens 40. The first ring group 21 includes multiple first fiber rings 211, and the second ring group 23 includes multiple second fiber rings 231. Therefore, each winding forms multiple first fiber rings 211 or multiple second fiber rings 231, which requires fewer winding operations and results in higher winding efficiency compared to each winding forming only one first fiber ring 211 or one second fiber ring 231. Since optical fiber transmission of optical signals suffers significant loss, the first collimating lens 30 and the second collimating lens 40 can convert the optical signal into a parallel beam for transmission, reducing signal attenuation. The embodiments of this application can solve the technical problem that the end of the delay fiber 20 is easily covered.

[0058] In some embodiments, please refer to Figure 1 and Figure 5 The fiber delay device 100 also includes a protective box 90; the support member 10 and part of the delay fiber 20 are fixed inside the protective box 90, and the first collimating lens 30 and the second collimating lens 40 are located outside the protective box 90.

[0059] The protective box 90 can isolate the support 10 and part of the delay fiber 20 from the external environment of the protective box 90, reduce the impact of the external environment of the protective box 90 on the support 10 and the delay fiber 20, and keep the support 10 and the delay fiber 20 stable.

[0060] The first collimating lens 30 and the second collimating lens 40 are located outside the protective box 90. That is, the input terminal 22 and the output terminal 24 are connected to the first collimating lens 30 and the second collimating lens 40 respectively outside the protective box 90. The first collimating lens 30 is located outside the protective box 90 for easy connection to external signal input devices. The second collimating lens 40 is located outside the protective box 90 for easy connection to external signal receiving devices.

[0061] In some embodiments, please refer to Figure 1 The fiber optic delay device 100 also includes multiple output optical fibers 41 and a first fiber optic coupler 70, which is fixed inside the protective box 90. One end of the first fiber optic coupler 70 is connected to the output end 24, and the other end of the first fiber optic coupler 70 is connected to multiple output optical fibers 41. Multiple second collimating lenses 40 are provided, and each of the multiple second collimating lenses 40 is connected to a corresponding output optical fiber 41.

[0062] The input end of the first fiber optic coupler 70 is connected to the output end 24 of the delay fiber 20, and the first fiber optic coupler 70 has an input port connected to the output end 24. The output end of the first fiber optic coupler 70 is connected to the output fiber 41, and the first fiber optic coupler 70 also has multiple output ports that are respectively connected to the two output fibers 41. The first fiber optic coupler 70 is capable of transmitting the optical signal transmitted by the delay fiber 20 to the two output fibers 41 respectively.

[0063] One end of each of the multiple output optical fibers 41 away from the first optical fiber coupler 70 is connected to a corresponding second collimating lens 40. The multiple output optical fibers 41 can receive the optical signal transmitted by the first optical fiber coupler 70 and transmit the optical signal to the corresponding second collimating lens 40, which then transmits it to the signal receiving device.

[0064] For example, if there are two second collimating lenses 40 and two output optical fibers 41, then the first fiber coupler 70 has two output ports, each connected to one of the two output optical fibers 41. Alternatively, if there are four second collimating lenses 40 and four output optical fibers 41, then the first fiber coupler 70 has four output ports.

[0065] The beneficial effects of this embodiment are as follows: setting two output optical fibers 41 and two second collimating lenses 40 enables the optical signal to be transmitted to two receiving terminal devices respectively. Using the first optical fiber coupler 70 enables the optical signal transmitted by the delay optical fiber 20 to be evenly distributed to the two output optical fibers 41, so that the optical signal can be stably transmitted in the two output components.

[0066] In some embodiments, please refer to Figure 1 The fiber optic delay device 100 also includes a first sleeve 50, which is connected to the protective box 90 and located outside the protective box 90, with the input end 22 passing through the first sleeve 50.

[0067] If the first sleeve 50 is located outside the protective box 90, then a portion of the delay fiber 20, including the input end 22, is inserted inside the first sleeve 50.

[0068] The beneficial effect of this application embodiment is that: since the input end 22 is inserted into the first sleeve 50, the first sleeve 50 can protect the part of the delay fiber 20 including the input end 22, so that the delay fiber 20 can stably transmit optical signals.

[0069] In some embodiments, please refer to Figure 1 The fiber delay device 100 also includes a second sleeve 60, which is connected to the protective box 90 and located outside the protective box 90, and the output fiber 41 passes through the second sleeve 60.

[0070] If the second sleeve 60 is located outside the protective box 90, then the portion of the output optical fiber 41 that passes through the second sleeve 60 is located outside the protective box 90. Optionally, the output optical fiber 41 can extend from inside the protective box 90 to outside the protective box 90, and the output optical fiber 41 is connected to the output end 24 inside the protective box 90. The protective box 90 can protect the output end 24.

[0071] The beneficial effect of this application embodiment is that: since the output optical fiber 41 is inserted into the second sleeve 60, the second sleeve 60 can protect the output optical fiber 41, so that the output optical fiber 41 can stably transmit optical signals.

[0072] In some embodiments, please refer to Figure 1 The fiber optic delay device 100 also includes a first sleeve 50, which is connected to and located outside the protective box 90, with the input end 22 passing through the first sleeve 50. The fiber optic delay device 100 also includes a second sleeve 60, which is connected to and located outside the protective box 90, with the output fiber optic cable 41 passing through the second sleeve 60.

[0073] In some embodiments, the difference in length between the two output optical fibers 41 is less than or equal to 0.5 mm.

[0074] When the length difference of the two output optical fibers 41 is greater than 0.5 mm, the synchronization of the optical signals output by the two output optical fibers 41 is poor. Optionally, the length difference of the two output optical fibers 41 can be 0.05 mm, resulting in higher synchronization of the optical signals output by the two output optical fibers 41. Optionally, the length difference of the two output optical fibers 41 can also be 0.5 mm, which makes the manufacturing difficulty of the output component lower. Optionally, the length difference of the two output optical fibers 41 can also be 0.4 mm, 0.3 mm, 0.25 mm, etc.

[0075] The beneficial effects of this application embodiment are that by limiting the length difference of the two output optical fibers 41 to the above range, the optical signals output by the two output optical fibers 41 can be highly synchronized, and the length difference of the two output optical fibers 41 is easy to control during manufacturing, and the output component is less difficult to manufacture.

[0076] In some embodiments, please refer to Figure 1 , Figure 5 and Figure 6 The protective box 90 includes a mounting wall 913, and one end of the support member 10 along the axis 13 is fixed to the mounting wall 913. At the end of the support member 10 along the axis 13 near the mounting wall 913, a first winding section and a second winding section respectively contact the support member 10 and extend to the mounting wall 913, and the first winding section and the second winding section are fixed to the mounting wall 913.

[0077] One end of the support member 10, which is fixed to the mounting wall 913, is designated as the fixed end 14. The first winding segment and the second winding segment extend from the fixed end 14 to the mounting wall 913. The first winding segment and the second winding segment respectively contact the support member 10, that is, the first winding segment and the second winding segment, located outside the first ring group 21 and the second ring group 23, extend on the surface of the support member 10 between the entire assembly and the mounting wall 913. The mounting wall 913 and the fixed end 14 can stably support the first winding segment and the second winding segment, keeping the first winding segment and the second winding segment stable.

[0078] In some embodiments, please refer to Figures 2 to 4 The support member 10 includes a support column 11 and two limiting plates 12. The length direction of the support column 11 is parallel to the axis 13. The two limiting plates 12 are respectively connected to the two ends of the support column 11 along its own length direction. The two limiting plates 12 are respectively used to block the movement of the first optical fiber ring 211 and the second optical fiber ring 231.

[0079] Optionally, the support column 11 can be a cylinder with axis 13 as the center line. When the delay fiber 20 is wound, it contacts the arc surface of the cylinder, resulting in less wear.

[0080] The length direction of the support column 11 is consistent with the length direction of the axis 13. The first optical fiber ring 211 and the second optical fiber ring 231 are wound around the support column 11. Two limiting plates 12 are respectively connected to the two ends of the support column 11 along its own length direction. In the length direction of the axis 13, the two limiting plates 12 are respectively located on both sides of the first optical fiber ring 211 and the second optical fiber ring 231 along the length direction. The two limiting plates 12 can prevent the first optical fiber ring 211 and the second optical fiber ring 231 from moving along the length direction of the support column 11, so that the first optical fiber ring 211 and the second optical fiber ring 231 are more stable on the support member 10.

[0081] Optionally, one of the limiting plates 12 is fixed to the mounting wall 913, and the fixed end 14 is located on the limiting plate 12.

[0082] Optionally, the limiting plate 12 can be perpendicular to the axis 13. The contact area between the limiting plate 12 and the first fiber ring 211 and the second fiber ring 231 is large, which can stably restrict the movement of the first fiber ring 211 and the second fiber ring 231.

[0083] In some embodiments, the protective box 90 is a titanium alloy component, and the support member 10 is a titanium alloy component, that is, the protective box 90 and the support member 10 are made of titanium alloy.

[0084] The beneficial effects of this application embodiment are as follows: Titanium alloy has a low coefficient of thermal expansion. Since the protective box 90 and the support member 10 are made of titanium alloy, the deformation of the protective box 90 and the titanium alloy is small in environments with large temperature differences, thus reducing the impact of the protective box 90 and the titanium alloy on the delay fiber 20. Furthermore, the titanium alloy protective box 90 can reduce ultraviolet damage to the delay fiber 20, making the fiber optic delay device 100 more suitable for environments with large temperature differences and strong ultraviolet radiation, such as space.

[0085] In some embodiments, the delay fiber 20 is an ultraviolet radiation resistant fiber, which can reduce the damage of ultraviolet rays to the delay fiber 20. The fiber delay device 100 is more suitable for environments with strong ultraviolet rays, such as space.

[0086] In some embodiments, the protective box 90 is a titanium alloy component, and the support 10 is a titanium alloy component. The time-delay fiber 20 is an ultraviolet radiation resistant fiber.

[0087] In some embodiments, the output optical fiber 41 is an ultraviolet radiation resistant optical fiber, which can reduce the damage of ultraviolet rays to the output optical fiber 41. The optical fiber delay device 100 is more suitable for environments with strong ultraviolet rays, such as space.

[0088] In some embodiments, the outer surface of the delay fiber 20 is provided with a first fixing adhesive, and the delay fiber 20 is bonded to the support member 10 by the first fixing adhesive; a plurality of first fiber rings 211 and a plurality of second fiber rings 231 are bonded together by the first fixing adhesive.

[0089] Optionally, when winding the first winding segment, the first fiber optic ring 211 is in direct contact with the support member 10 and is bonded by the first fixing adhesive.

[0090] Optionally, when winding the second winding section first, the second fiber optic ring 231 is in direct contact with the support member 10 and is bonded by the second fixing adhesive.

[0091] The first fixing adhesive is located on the outer surface of the time-delay fiber 20. As the time-delay fiber 20 is wound, the first fixing adhesive is automatically distributed between the support member 10 and the time-delay fiber 20, between adjacent first winding rings in a first fiber ring 211, between adjacent first fiber rings 211 in a first ring group 21, between adjacent second winding rings in a second fiber ring 231, between second fiber rings 231 in a second ring group 23, and between adjacent first ring groups 21 and second ring groups 23. The first fixing member can stably bond multiple first fiber rings 211 and multiple second fiber rings 231 to the support member 10, so that the time-delay fiber 20 remains stable.

[0092] Optionally, the first fixing adhesive can be photosensitive adhesive, also known as shadowless adhesive. The first fixing adhesive can be cured with ultraviolet light after the delay fiber 20 is wound, which makes it easy to correct errors during the winding process.

[0093] The beneficial effect of this application embodiment is that: a first fixing adhesive is provided on the outer surface of the delay optical fiber 20, so that after the delay optical fiber 20 is wound, the position where the delay optical fiber 20 contacts the support member 10 and the outer surface of adjacent delay optical fibers 20 can be bonded together by the first fixing adhesive, and the connection between the delay optical fiber 20 and the support member 10 is relatively stable.

[0094] In some embodiments, please refer to Figures 2 to 4 First fiber optic rings 211 are respectively provided on the inner and outer sides of the first ring group 21 and the second ring group 23 along the radial direction. The first ring group 21 and the second ring group 23 are nested between the two first fiber optic rings 211 along the radial direction. The inner and outer sides of the first ring group 21 and the second ring group 23 along the radial direction are both the second ring group 23.

[0095] In some embodiments, the length of the first winding segment is equal to the length of the second winding segment. The number of first fiber loops 211 formed by the first winding segment and the number of second fiber loops 231 formed by the second winding segment are substantially equal. The number of first fiber loops 211 in each first loop group 21 and the number of second fiber loops 231 in each second loop group 23 can be the same. The same method can be used for each winding of the first winding segment and each winding of the second winding segment, making the winding process of the delay fiber 20 relatively simple.

[0096] In some embodiments, please refer to Figure 1 and Figure 6 The first collimating lens 30 has an input optical fiber. The input end 22 of the delay optical fiber 20 is fused to the input optical fiber to form a fusion point. The output end 24 of the delay optical fiber 20 is fused to the first optical fiber coupler 70 to form a fusion point. The first optical fiber coupler 70 is fused to the output optical fiber 41 to form a fusion point. The optical fiber delay device 100 also includes multiple fusion protection sleeves 80 respectively fitted at multiple fusion points to protect the fusion points. The fusion protection sleeves 80 and the first optical fiber coupler 70 are bonded to the mounting wall 913 by a second fixing adhesive.

[0097] In some embodiments, please refer to Figure 5 and Figure 6The protective box 90 includes a box body 91 and a box cover 92. A mounting wall 913 is located on the box body 91. The box body 91 has multiple through holes 911 and multiple threaded holes 912, with each threaded hole 912 corresponding to one of the through holes 911, and the threaded holes 912 intersecting with their corresponding through holes 911. The delay fiber 20 and the output fiber 41 extend outside the box body 91 through the multiple through holes 911. One end of the first sleeve 50 and one end of the second sleeve 60 are respectively located in the corresponding through holes 911. The fiber delay device 100 also includes multiple screws, which are screwed into the multiple threaded holes 912 and fixedly connected to the first sleeve 50 and the second sleeve 60 through the threaded holes 912.

[0098] In some embodiments, the first sleeve 50 and the second sleeve 60 are configured as stainless steel tubes encasing black thermoplastic polyurethane (TPU) elastomer. The thermoplastic polyurethane elastomer forms an outer tube with an outer diameter of 3.0 mm, while the stainless steel tube has an inner diameter of 1.6 mm and an outer diameter of 2.1 mm. This provides UV protection and high strength, resulting in good protection for the time-delay optical fiber 20.

[0099] In some embodiments, please refer to Figures 1 to 7 The method for manufacturing the fiber optic delay device 100 includes:

[0100] S1. Before winding the time-delay fiber 20, inspect the fiber, support 10, and adhesive. Incoming inspection of the time-delay fiber 20 is performed, and then the length of the time-delay fiber 20 is calculated based on the phase delay. The time-delay fiber 20 is divided into a first winding segment and a second winding segment from its midpoint, and marking points are made at two predetermined distances from both ends of the time-delay fiber 20. Incoming inspection of the support 10 is performed, followed by cleaning and drying. Incoming inspection of the adhesive is performed; the adhesive includes photosensitive adhesive and a second fixing adhesive.

[0101] When the operating wavelength is greater than the cutoff wavelength, the optical fiber operates in single-mode; if the wavelength is less than the cutoff wavelength, higher-order modes (such as LP) will be excited. 11 The presence of multiple modes (phase delay) leads to multimode transmission. For an optical fiber delay device 100, phase delay is a crucial technical indicator. If multimode transmission occurs within the optical fiber, the signal pulse will be broadened, and the phase delay will be uncertain. The cutoff wavelength formula is as follows:

[0102]

[0103] Wherein, λc is the cutoff wavelength, which is also the wavelength in a single-mode fiber that can only transmit the fundamental mode (LP). 01 The minimum wavelength of the mode; a is the core radius; NA is the numerical aperture of the optical fiber.

[0104] The optical fiber is selected based on the cutoff wavelength formula. For example, the operating wavelength of the fiber delay device 100 is 532.2 ± 1 nm, which falls within the green light band. The parameters of the delay fiber 20 and the output fiber 41 are as follows: core diameter of 0.0000029 m, numerical aperture (NA) of 0.13, core refractive index n1 of 1.4652, cladding refractive index n2 of 1.4594, attenuation less than or equal to 30 dB / km, cladding diameter of 125 ± 1 μm, and coating diameter of 245 ± 7 μm. The single-mode cutoff wavelength λc is calculated to be 492 nm according to the cutoff wavelength formula, thus ensuring that the 532.2 nm signal is not broadened. The delay fiber 20 and the output fiber 41 are made of pure silicon core single-mode fiber resistant to ultraviolet radiation, suitable for transmitting purple, blue, and green wavelengths.

[0105] For example, the phase delay of the fiber optic delay device 100 is 6666.7 ± 0.1 ns. The fiber length = speed of light in vacuum × phase delay / core refractive index. The speed of light in vacuum = 299,792,458 m / s. The calculated total length of the delay fiber 20 and one output fiber 41 ranges from 1364.04 m to 1368.08 m. The volume of the delay fiber 20 is approximately 67178.5 mm². 3 For example, the volume of support 10 is set to 132889.4 mm². 3 The volume of the support member 10 is the volume of the space enclosed by the two limiting plates 12 and the support column 11, which can wrap all the optical fibers around the support column 11 between the two limiting plates 12.

[0106] S2, Winding the delay fiber 20; Assemble the support 10 onto the fiber winding device, and alternately wind the first and second winding segments between the two marked points onto the support 10, forming alternating first loop groups 21 and second loop groups 23. Photosensitive adhesive is coated onto the delay fiber 20 during the winding process. End face preparation and cleaning are performed on pigtails not located between the two marked points to enable them to connect to other devices.

[0107] For example, when winding a first ring group 21, the first first fiber ring 211 is first wound from left to right, and then the first winding segment is wound from the right end of the first first fiber ring 211 to the left end of the first fiber ring 211. A second first fiber ring 211 is formed on the radial outer side of the first first fiber ring 211. The two first fiber rings 211 form a first ring group 21.

[0108] For example, when winding a second ring group 23, the first second fiber optic ring 231 is wound from left to right. Then, the first winding segment is wound from the right end of the first second fiber optic ring 231 to the left end of the second fiber optic ring 231. A second second fiber optic ring 231 is formed on the radially outer side of the first second fiber optic ring 231. The two second fiber optic rings 231 form a second ring group 23.

[0109] For example, when alternately winding the first winding segment and the second winding segment, the first winding segment can be wound clockwise to form a first loop group 21, and then the second winding segment can be wound counterclockwise to form a second loop group 23, and the above process can be repeated.

[0110] Optionally, the winding tension of the time-delay fiber 20 is set to 6g.

[0111] S3, after winding the delay fiber 20, fix the delay fiber 20; after the delay fiber 20 is wound, cure the photosensitive adhesive with ultraviolet (UV) light and age the photosensitive adhesive.

[0112] For example, the curing time is 40 min, the aging temperature is 85℃, and the aging time is 12 H.

[0113] S4, Assemble the fiber optic delay device 100; use the first sleeve 50 and the second sleeve 60 to respectively cover the delay fiber 20 and the output fiber 41, and use the fusion splice protection sleeve 80 to cover the delay fiber 20 and the output fiber 41. Fusion splice the input end 22 of the first winding section to the first collimating lens 30, fusion splice the output end 24 of the second winding section to the input port of the first fiber optic coupler 70, and fusion splice the two output ports of the first fiber optic coupler 70 to the two output fibers 41 respectively. Place the support 10 into the protective box 90 and fix it to the mounting wall 913. Place the fusion splice protection sleeve 80 in the fusion position. Use the second fixing adhesive to bond the first fiber optic coupler 70 and the fusion splice protection sleeve 80 to the mounting wall 913. Use screws to fix the first sleeve 50 and the second sleeve 60, and use screws to fix the support frame to the mounting wall 913.

[0114] For example, the protective box 90 is a square box with dimensions of 110mm × 110mm × 66.5mm, capable of accommodating the support member 10. For example, the coupler has one input port and two output ports, operates at a wavelength of 532 nm, is suitable for fiber optic applications in the green light band, and has a splitting ratio of 50:50 between the two output ports.

[0115] For example, the total weight of the fiber optic delay device 100 is less than or equal to 1000g. The support member 10 and protective box 90 are designed with a hollow structure, so the combined weight of the protective box 90 and support member 10 is approximately 550g. The total weight of the delay fiber 20, output fiber 41, first fiber coupler 70, fusion splice protective sleeve 80, screws, photosensitive adhesive, and second fixing adhesive is approximately 260g. The total weight of the first sleeve 50, second sleeve 60, first collimating lens 30, and second collimating lens 40 is approximately 110g. The total weight of the fiber optic delay device 100 is approximately 920g.

[0116] For example, the link transmission efficiency of the fiber delay device 100 is set to be greater than or equal to 0.25%, wherein the insertion loss (IL) of the coupler is ≤3.8dB, the insertion loss (IL) of the input and output collimators is ≤2.2dB, the insertion loss (IL) of the delay fiber 20 is ≤19.0dB, and the total insertion loss (IL) of the link transmission is ≤25dB, which translates to an efficiency of 0.32%, meeting the design requirement of a link transmission efficiency ≥0.25%.

[0117] Optical fiber, as a transmission medium, introduces a time delay when optical signals propagate within it. Precise time delay control can be achieved by adjusting the fiber's length. Phase delay is a crucial indicator of the optical fiber delay device 100, and the measurement method and accuracy of phase delay are extremely important, playing a key role in the accuracy of satellite remote sensing systems.

[0118] Currently, phase delay is mainly measured using expensive equipment such as optical time domain reflectometers (OTDR), which has low testing efficiency and large testing errors (1ns), thus seriously affecting the accuracy of satellite remote sensing and image clarity.

[0119] To address the aforementioned technical problems, the second aspect of this application also provides a delay measurement device 200, which is used to measure the fiber optic delay device 100 in any of the first aspect embodiments.

[0120] Please refer to Figure 8The delay measurement device 200 includes a light source 201, a connecting optical fiber 202, a second optical fiber coupler 204, and a reference optical fiber 205 connected in sequence. The second optical fiber coupler 204 is used to connect the connecting optical fiber 202 and the second collimating lens 40. The delay measurement device 200 also includes an oscilloscope 206 and two photoelectric converters 207. The photoelectric converters 207 are electrically connected to the oscilloscope 206. The two photoelectric converters 207 are used to convert the optical signal output from the first collimating lens 30 and the optical signal output from the reference optical fiber 205 into electrical signals and transmit them to the oscilloscope 206. The oscilloscope 206 is used to measure the phase delay between the electrical signals transmitted by the two photoelectric converters 207.

[0121] The light source 201 is used to emit optical signals. Optionally, the light source 201 can be a pulsed laser, capable of adjusting pulse parameters to adapt to the detection requirements of different optical fibers. For example, the light source 201 is a water-cooled green nanosecond pulsed laser with a working wavelength of 532.1 nm and an output power of 10 W, capable of measuring the optical fiber delay device 100 with a working wavelength of 532.2 ± 1 nm in the first aspect embodiment.

[0122] Optionally, the light source 201 and the connecting optical fiber 202 can be connected by a ceramic ferrule 210, which has an outer diameter of 2.5 mm and an inner diameter of 0.405 mm, to accommodate the connecting optical fiber 202 and the light source 201.

[0123] Optionally, the connecting fiber 202 may include a first connecting fiber 2021 and a second connecting fiber 2022. Optionally, the first connecting fiber 2021 and the second connecting fiber 2022 can be connected via a mode field adapter 203 (MFA), enabling the use of first connecting fibers 2021 and 2022 with different mode field diameters and vertical apertures to connect the light source 201 to the second fiber coupler 204. For example, the core diameter of the first connecting fiber 2021 may be 50 μm, the cladding diameter may be 400 μm, the core numerical aperture may be 0.12, and the cladding numerical aperture may be 0.46. For example, the second connecting fiber 2022 may be a single-mode fiber with an operating wavelength of 400 nm, suitable for visible light transmission.

[0124] The second fiber optic coupler 204 has one input port connected to the connecting fiber optic cable 202 and two output ports. One output port of the second fiber optic coupler 204 is connected to the reference fiber optic cable 205, and the other output port is used to connect to the second collimating lens 40. During testing, the second fiber optic coupler 204 can transmit optical signals to the reference fiber optic cable 205 and the second collimating lens 40 respectively. For example, the operating wavelength of the second fiber optic coupler 204 is 532 nm, and the splitting ratio of the two output ports is 0.1:99.9, which can output 99.9% of the light to the second collimating lens 40, so that the optical signal can be stably output from the fiber optic delay device 100.

[0125] Optionally, the second fiber optic coupler 204 can be connected to the second collimating lens 40 via the fiber optic connector 208 and the adapter 209, enabling stable transmission of optical signals to the second collimating lens 40.

[0126] The reference fiber 205 is relatively short, enabling rapid transmission of optical signals to the photoelectric converter 207. Based on the different transmission times of the optical signal in the reference fiber 205 and the fiber delay device 100, the phase delay of the fiber delay device 100 can be measured.

[0127] Optionally, the oscilloscope 206 can be a high-precision digital oscilloscope 206 to ensure measurement accuracy.

[0128] Optionally, the photoelectric converter 207 can be a photodetector with a response wavelength range of 200 to 1100 nm, capable of stably receiving the optical signal output by the first collimating lens 30.

[0129] During measurement, the output terminal 24 of the second fiber coupler 204 is connected to a second collimating lens 40, controlling the light source 201 to output pulsed light. The pulsed light is transmitted through the connecting fiber 202 and the second fiber coupler 204 to the reference fiber 205 and the second collimating lens 40, respectively. The optical signal output from the reference fiber 205 is converted into an electrical signal by the corresponding photoelectric converter 207 and transmitted to the oscilloscope 206, displaying the pulse signal T1. The optical signal transmitted by the second collimating lens 40 is transmitted through the delay fiber 20 to the first collimating lens 30. The optical signal output from the first collimating lens 30 is converted into an electrical signal by the corresponding photoelectric converter 207 and transmitted to the oscilloscope 206, displaying the pulse signal T2. When the fiber delay device 100 includes a first fiber coupler 70 and an output fiber 41, the optical signal transmitted by the second collimating lens 40 is transmitted sequentially through the output fiber 41, the first fiber coupler 70, and the delay fiber 20 to the first collimating lens 30. After setting the operating parameters of the oscilloscope 206, move the two vertical scales of the oscilloscope 206 to the same characteristic point positions on the pulse signal T1 and pulse signal T2, respectively. For example, move the two vertical scales of the oscilloscope 206 to the peak point of pulse signal T1 and the peak point of pulse signal T2, respectively. Then you can calculate the phase delay ΔT, which is the time difference between the peak point of pulse signal T2 and the peak point of pulse signal T1.

[0130] The beneficial effects of this application embodiment are as follows: using the same light source 201 can output the same optical signal to the reference optical fiber 205 and the optical fiber delay device 100, reducing the impact of optical signal errors on the measurement. The photoelectric conversion device can convert the optical signal into an electrical signal and transmit it to the oscilloscope 206, enabling the oscilloscope 206 to measure the phase delay of the two optical signals. The oscilloscope 206 has high reading accuracy, and using the oscilloscope 206 can accurately measure the phase delay of the optical signal transmitted in the reference optical fiber 205 relative to the optical signal transmitted in the reference optical fiber 205, thus solving the technical problem of large phase delay measurement errors.

[0131] In some embodiments, multiple fiber optic delay devices 100 are fabricated. The preset phase delay of the multiple fiber optic delay devices 100 is 6666.7 ns, the preset operating wavelength is 532.2 nm, the preset link transmission efficiency is greater than or equal to 0.25%, and the preset total weight is less than or equal to 1000 g. The actual operating wavelength, actual link transmission efficiency, and total weight of the fiber optic delay devices 100 are measured, and the phase delay is measured using a delay measurement device 200. The measurement data are shown in Table 1.

[0132] Table 1. Measured performance data of fiber optic delay device 100

[0133]

[0134] As shown in Table 1, the phase delay of the multiple fiber delay devices 100 is 6666.7±0.1ns, the working wavelength is 532.2nm, the link transmission efficiency is greater than 0.25%, and the total weight is less than 1000g. The phase delay error of this fiber delay device 100 is small, and the link transmission efficiency, total weight and other indicators all meet the design technical requirements.

[0135] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A fiber optic delay device, characterized in that, include: Support components; The time-delay fiber includes a first winding segment and a second winding segment connected to the first winding segment. The first winding segment is wound around an axis on the support to form a first fiber loop, and multiple first fiber loops are nested radially to form multiple first loop groups. The second winding segment is wound around the axis on the support to form a second fiber loop, and multiple second fiber loops are nested radially to form multiple second loop groups. The second loop groups and the first loop groups are nested together radially and alternately arranged. The end of the first winding segment away from the second winding segment is the input end, and the end of the second winding segment away from the first winding segment is the output end. Both the input end and the output end extend beyond each first loop group and each second loop group. A first collimating lens is connected to the input terminal; A second collimating lens is connected to the output terminal.

2. The fiber optic delay device as described in claim 1, characterized in that, The fiber delay device also includes a protective box; the support member and part of the delay fiber are fixed inside the protective box; the first collimating lens and the second collimating lens are located outside the protective box.

3. The fiber optic delay device as described in claim 2, characterized in that, The fiber delay device further includes multiple output fibers and a first fiber coupler. The first fiber coupler is fixed inside the protective box. One end of the first fiber coupler is connected to the output end, and the other end of the first fiber coupler is connected to multiple output fibers. Multiple second collimating lenses are provided, and each of the multiple second collimating lenses is connected to a corresponding output fiber.

4. The fiber optic delay device as described in claim 3, characterized in that, The fiber optic delay device further includes a first sleeve, which is connected to the protective box and located outside the protective box, with the input end passing through the first sleeve; and / or The fiber delay device also includes a second sleeve, which is connected to the protective box and located outside the protective box, and the output fiber passes through the second sleeve.

5. The fiber optic delay device as described in claim 3, characterized in that, The difference in length between the two output optical fibers is less than or equal to 0.5 mm.

6. The fiber optic delay device as described in claim 2, characterized in that, The protective box includes a mounting wall, and one end of the support member along the axis is fixed to the mounting wall; at the end of the support member along the axis near the mounting wall, the first winding section and the second winding section respectively contact the support member and extend to the mounting wall, and the first winding section and the second winding section are fixed to the mounting wall.

7. The fiber optic delay device as described in claim 6, characterized in that, The support includes a support column and two limiting plates. The length direction of the support column is parallel to the axis. The two limiting plates are respectively connected to the two ends of the support column along its own length direction. The two limiting plates are respectively used to block the movement of the first optical fiber ring and the second optical fiber ring.

8. The fiber optic delay device as described in any one of claims 2-7, characterized in that, The protective box is a titanium alloy component, the support component is a titanium alloy component; and / or, The delay fiber is an ultraviolet radiation resistant fiber.

9. The fiber optic delay device as described in any one of claims 1-7, characterized in that, The outer surface of the delay fiber is provided with a first fixing adhesive, and the delay fiber is bonded to the support member by the first fixing adhesive; a plurality of first fiber rings and a plurality of second fiber rings are bonded together by the first fixing adhesive.

10. A device for measuring time delay, characterized in that, The delay measurement device is used to measure the fiber optic delay device according to any one of claims 1-9; the delay measurement device includes a light source, a connecting fiber, a second fiber coupler, and a reference fiber connected in sequence; the second fiber coupler is used to connect the connecting fiber to the second collimating lens; the delay measurement device further includes an oscilloscope and two photoelectric converters, the photoelectric converters are electrically connected to the oscilloscope, the two photoelectric converters are respectively used to convert the optical signal output from the first collimating lens and the optical signal output from the reference fiber into electrical signals and transmit them to the oscilloscope; the oscilloscope is used to measure the phase delay between the electrical signals transmitted by the two photoelectric converters.

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