Apparatus and method for manufacturing an optical fiber coil having an ultra-large diameter

Abstract

The application discloses a device and a method for preparing an optical fiber coil with an ultra-large diameter, and belongs to the technical field of optical fiber coil preparation. The device comprises a fiber supply unit, an expandable loop forming unit and an electrical control system. The fiber supply unit is provided with a tension adjusting mechanism to stabilize the fiber tension and the feeding speed, and is matched with a visual auxiliary adjusting mechanism to ensure the laying position accuracy. The expandable loop forming unit adopts a flexible expansion combination structure, which is suitable for different size optical fiber coil product diameter requirements, and is matched with a fiber position holder made of the same material to limit the optical fiber, and a belt-shaped flexible lining is arranged on the steel belt. During preparation, the loop forming unit is assembled as required and the fiber position holder is laid, then the fiber is fixed by the fiber supply unit, the optical fiber is laid layer by layer and the fiber position holder is installed, and after forming, the support parts are disassembled to obtain the finished product. The device can be flexibly expanded and combined, and can prepare an ultra-large diameter optical fiber coil with a meter level, a ten-meter level or even a larger size. The finished optical fiber coil has stable laying accuracy, can be folded for transportation, and expands the application field of the optical fiber coil.

Description

Technical Field

[0001] This invention belongs to the field of optical fiber loop fabrication technology, specifically relating to an apparatus and method for fabricating ultra-large diameter optical fiber loops. Background Technology

[0002] Fiber optic loops are ring-shaped optical sensing elements formed by winding optical fibers and solidifying them with an adhesive. They are core components of traditional instruments such as fiber optic gyroscopes and fiber optic current transformers. With technological advancements, the application areas of these elements are constantly expanding, such as in large-scale equipment for measuring seismic waves in geological surveying. However, due to the high sensitivity requirements, the specifications of the fiber optic loops needed differ from traditional products. Specifically, commercially available fiber optic loops are generally within 300 mm in diameter, while the diameter requirements for fiber optic loops in geological surveying are in the meter range, and even require diameters of 20, 30 meters, or even larger. Constrained by the ring-forming process and the structure of the ring-making equipment itself, existing ring-making equipment cannot produce excessively large fiber optic loops. Currently, the largest fiber optic loop product reported domestically and internationally has a diameter of 2 meters, which is close to the limit of existing ring-making equipment. How to overcome the limitations of existing ring-making equipment and processes to conveniently and effectively produce ultra-large diameter fiber optic loops has become crucial for this element to enter new fields. Summary of the Invention

[0003] This invention addresses the shortcomings of existing technologies by proposing an apparatus and method for fabricating ultra-large diameter fiber loops. This method allows for the flexible fabrication of fiber loop products with different diameters, thereby solving the problem of fabricating ultra-large diameter fiber loops.

[0004] One of the above-mentioned objectives of the present invention is achieved by the following technical solution: An apparatus for fabricating ultra-large diameter optical fiber loops includes a fiber supply unit, an expandable looping unit, and an electrical control system. In the fiber supply unit, the fiber material on the fiber supply tray is guided by a fiber guide pulley system and then output to the expandable looping unit, where the large-diameter optical fiber loop is fabricated. The fiber supply unit includes a tension adjustment mechanism for adjusting the fiber supply tension and a visual auxiliary adjustment mechanism for adjusting the positional accuracy of the fiber during looping. The expandable looping unit adopts a flexible expansion assembly structure matched to the diameter of the optical fiber loop, including multiple support rollers and steel... The system comprises a steel strip, support feet, a flexible inner liner, fiber position retainers, and a ring-forming drive motor. Each support roller is rotatably supported at both ends on a pair of support feet. Multiple support rollers are arranged at a set interval, and the number of support rollers is determined according to the diameter of the fiber loop. A steel strip is wrapped around multiple support rollers and rotates with them. The flexible inner liner is fitted to the outside of the steel strip and rotates with it. The fiber position retainer located at the innermost layer of the fiber loop is fixed to the surface of the flexible inner liner. During the fabrication of the fiber loop, a certain number of fiber position retainers are provided between the fibers in adjacent layers.

[0005] Furthermore, the fiber supply unit also includes a fiber supply worktable, a reciprocating slide, a slide drive mechanism, and a vertical support frame. The reciprocating slide is connected to the upper end of the fiber supply worktable via a linear guide rail and moves left and right reciprocally via the slide drive mechanism. The vertical support frame is vertically fixed to the upper end of the reciprocating slide and is used to install the fiber supply tray, fiber guide pulley group, tension adjustment mechanism, and visual auxiliary adjustment mechanism. The fiber supply tray is a storage tray for optical fibers, and the fiber supply tray is installed on the tray shaft on the front of the vertical support. The tray shaft is driven by a fiber supply motor. The fiber guide pulley group is used to guide the optical fibers output from the fiber supply tray.

[0006] Moreover, the fiber guide pulley assembly consists of four fiber guide pulleys, three of which are installed at the high end of the front of the vertical support frame at the same height, and the other fiber guide pulley is installed at the low end of the vertical support frame on the side near the expandable ring unit.

[0007] Furthermore, the tension adjustment mechanism is located in the space between the three fiber guide pulleys at the high end and the fiber supply tray, and consists of a tension adjustment wheel, a tension adjustment arm, and an angle encoder. One end of the tension adjustment arm is fixed on the tension adjustment shaft, which is rotatably and vertically connected to the vertical support frame. The other end of the tension adjustment arm is rotatably connected to the tension adjustment wheel. The angle encoder is coaxially fixed on the tension adjustment shaft.

[0008] Moreover, the vision-assisted adjustment mechanism is located at the end of the fiber supply unit and consists of a vision sensor, a fiber guide nozzle, and a micro motor. The fiber guide nozzle is used to guide the output of the material optical fiber.

[0009] Moreover, the fiber position retainer is made of the same material as the ring-filled adhesive used in subsequent processes and is manufactured by 3D printing. The fiber position retainer is strip-shaped, with semi-circular grooves evenly distributed along the length of the strip at its upper and lower ends. The semi-circular grooves at the upper and lower ends are staggered, and the radius of the semi-circular grooves matches the diameter of the optical fiber.

[0010] Moreover, the strip-shaped flexible liner is made of polyurethane, PVC, fluororubber or silicone rubber.

[0011] The second objective of this invention is achieved through the following technical solution: A method for fabricating fiber loops based on the aforementioned apparatus capable of fabricating ultra-large diameter fiber loops includes the following steps: Step 1: Select appropriate sizes of steel strips, flexible inner lining strips, and a reasonable number of support feet and support rollers according to the diameter of the fiber optic ring, assemble them, install ring drive motors at both ends, and then attach several fiber position retainers to the surface of the flexible inner lining strip in reasonable segments according to the actual size of the fiber optic ring. Step 2: Install the pre-treated fiber supply tray containing the fiber material onto the tray shaft of the fiber supply unit. After passing the two fiber guide pulleys at the front end, the tension adjustment wheel, the two fiber guide pulleys at the rear end, and the fiber guide nozzle, guide the fiber material into the semi-circular groove on one side of the fiber position holder and fix it with adhesive. Step 3: Start the ring-forming drive motor, fiber supply motor and slide table drive mechanism to make the fiber optic ring. During the process of making the fiber optic ring, the material fiber in the fiber position holder is adhered with adhesive. After each layer of fiber is laid, the fiber position holder is adhered and installed on the corresponding bottom layer of fiber position holder. Then continue to lay the next layer of material fiber, and repeat this process until the fiber optic ring is made. Step 4: After the fiber optic ring is manufactured, the support feet, support rollers, and steel strip are removed in sequence to obtain a complete fiber optic ring product.

[0012] The advantages and positive effects of this invention are as follows: This invention proposes an apparatus and method for fabricating optical fiber loops. Unlike existing loop fabrication equipment, this apparatus restructures the loop fabrication equipment with a modular and flexible expansion design concept. This apparatus can be flexibly combined and expanded to adapt to the fabrication of different large-diameter optical fiber loop products, thereby overcoming the problem of fabricating meter-sized, ten-meter-sized, and even larger diameter optical fiber loop products that existing loop fabrication equipment cannot effectively solve. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention; Figure 2 This is a schematic diagram of the fiber supply unit of the present invention; Figure 3 This is a schematic diagram of the working principle of the fiber supply unit of the present invention; Figure 4 This is a schematic diagram of the working principle of the mechanical part of the vision-assisted adjustment mechanism of the present invention; Figure 5 This is a schematic diagram of the expandable ring-forming unit structure of the present invention; Figure 6 This is a schematic diagram of the overall structure of the fiber position retainer of the present invention; Figure 7 This is a partially enlarged view of the fiber position retainer of the present invention; Figure 8 This is a schematic diagram illustrating the working principle of the device of the present invention for preparing optical fiber loops; Figure 9 This is a schematic diagram of the installation of the fiber position retainer during the fiber loop fabrication process of the rotating shaft of the present invention; Figure 10 This is an enlarged view of the fiber positioning cage used to limit the optical fiber in this invention; Figure 11 This is a magnified cross-sectional view of the fiber positioning cage used in this invention to limit the optical fiber. Figure 12 This is a schematic diagram illustrating the process of the optical fiber loop product being removed from the equipment after the loop is formed according to the present invention.

[0014] The components include: 1. Fiber supply unit; 1-1. Fiber supply workbench; 1-2. Reciprocating sliding table; 1-3. Fiber supply tray; 1-4. Tension adjustment mechanism; 1-4-1. Tension adjustment wheel; 1-4-2. Tension adjustment arm; 1-4-3. Angle encoder; 1-5. Vertical support frame; 1-6. Fiber guide pulley group; 1-7. Vision-assisted adjustment mechanism; 1-7-1. Vision sensor; 1-7-2. Fiber guide nozzle; 1-7-3. Micro motor; 1-8. Fiber supply motor; 2. Expandable ring forming unit; 2-1. Ring forming drive motor; 2-2. Support roller; 2-3. Fiber position holder; 2-3-1. Semi-circular groove; 2-4. Steel strip; 2-5. Strip flexible liner; 2-6. Support foot; 3. Electrical control system; 4. Material optical fiber; 5. Fiber ring product. Detailed Implementation

[0015] The structure of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] For an apparatus capable of fabricating ultra-large diameter fiber loops, please refer to [link / reference]. Figures 1-12The device mainly consists of two parts: a fiber supply unit and a scalable ring forming unit. In the fiber supply unit, the fiber material 4 on the fiber supply tray is guided by the fiber guide pulley group and then supplied to the scalable ring forming unit, where a large-diameter fiber ring product is finally formed. The fiber supply unit uses an angle sensor and tension adjustment wheel to stabilize the fiber laying tension and feed speed, and a vision-assisted adjustment mechanism to ensure the positional accuracy of the fiber during loop laying. The expandable looping unit can be flexibly expanded and combined to adapt to the diameter size required by different fiber loop products. During the looping process, a dedicated fiber position holder is used to fix the position of the fiber. After the fiber loop product is completed, it is removed from the expandable looping unit along with the bottom strip flexible inner liner. Although the product is not cured with adhesive as in traditional small-sized products, the relative positions of the fibers in the entire loop product can still remain unchanged due to the combined effect of the strip flexible inner liner and the fiber position holder. Since it is not cured with adhesive, the product can be folded multiple times to reduce its volume for easy transportation.

[0017] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention. See also: Figure 1 The device of this invention generally consists of a fiber supply unit 1, an expandable loop forming unit 2, and an electrical control system 3. In this invention, a fiber supply unit is provided at each end of the expandable loop forming unit along the fiber winding direction, enabling multi-pole symmetrical winding processes. The electrical control system is located on one side of the expandable loop forming unit and is used to control fiber feeding and fiber loop winding.

[0018] Figure 2 For a 3D view of the fiber supply unit, see [link / reference]. Figure 2The fiber supply unit of this invention mainly includes a fiber supply worktable 1-1, a reciprocating slide 1-2, a slide drive mechanism (not shown in the attached drawings), a vertical support frame 1-5, a fiber supply tray 1-3, a fiber guide pulley group 1-6, a tension adjustment mechanism 1-4, and a vision-assisted adjustment mechanism 1-7. The reciprocating slide is connected to the upper end of the fiber supply worktable via a linear guide rail and can move left and right reciprocally via the slide drive mechanism. The slide drive mechanism can realize a screw and nut transmission mechanism, etc. The vertical support frame is vertically fixed to the upper end of the reciprocating slide and is used to install the fiber supply tray, the fiber guide pulley group, the tension adjustment mechanism, and the vision-assisted adjustment mechanism. The fiber supply tray is a storage tray for optical fibers, and it is installed on a tray shaft on the front of the vertical support. The tray shaft is driven by a fiber supply motor 1-8. The fiber guide pulley group is used to guide the optical fibers output from the fiber supply tray. The fiber guide pulley group consists of multiple fiber guide pulleys. In this invention, it consists of four fiber guide pulleys. Three fiber guide pulleys are installed at the high end of the vertical support frame at the same height on the front, while the other fiber guide pulley is installed at the low end of the vertical support frame near the expandable ring-forming unit. The tension adjustment mechanism and the visual-assisted adjustment mechanism are the core structures of the fiber supply unit.

[0019] Figure 3 Schematic diagram of fiber supply unit operation: After the expandable ring forming unit 2 is in operation, the motor in the fiber supply unit 1 rotates accordingly, supplying the fiber material in the fiber supply tray to the expandable ring forming unit 2 for laying through the first fiber guide pulley, the second fiber guide pulley, the tension adjustment wheel (also known as the dance wheel) of the tension adjustment mechanism, the third fiber guide pulley, the fourth fiber guide pulley, and the fiber guide nozzle of the vision-assisted adjustment mechanism.

[0020] The tension adjustment mechanism is located in the space between the three fiber guide pulleys at the high end and the fiber supply tray, and consists of a tension adjustment wheel 1-4-1, a tension adjustment arm 1-4-2, and an angle encoder 1-4-3. One end of the tension adjustment arm is fixed to the tension adjustment shaft, which is rotatably vertically connected to the vertical support frame. The other end of the tension adjustment arm is rotatably connected to the tension adjustment wheel. The angle encoder is coaxially fixed to the tension adjustment shaft. The tension adjustment wheel and tension adjustment arm constitute the dance wheel device. When the rotational speed of the fiber supply motor does not match the operating speed of the expandable ring forming unit 2, or when the fiber supply rate changes due to the change in the diameter of the material fiber coiled in the fiber supply tray, the material fiber will tighten or loosen accordingly, causing a change in the tension of the material fiber. At this time, the dancing wheel device in the tension adjustment mechanism will rotate from the initial zero position to rise or fall around the tension adjustment shaft connected to the angle encoder. After the angle encoder detects the angle signal, it feeds back to the electrical control system 3, which then controls the fiber supply motor to adjust its rotational speed to adapt to the operating speed of the expandable ring forming unit 2, adjusting the dancing wheel device back to the initial zero position to maintain the tension of the material fiber, thereby achieving the purpose of stabilizing the fiber laying tension and feed speed.

[0021] Figure 4 This is a schematic diagram of the working principle of the mechanical part of the vision-assisted adjustment mechanism of the present invention. The vision-assisted adjustment mechanism is located at the end of the fiber supply unit and mainly consists of a vision sensor 1-7-1, a fiber guide nozzle 1-7-2, and a micro motor 1-7-3. The optical fiber is supplied to the expandable looping unit 2 through the fiber guide nozzle 1-7-2, which structurally restricts the fiber's position, and is ultimately laid into a loop. When the fiber supply unit 1 performs lateral fiber arrangement, defects in the optical fiber itself or dimensional inaccuracies in the expandable looping unit 2 can cause the optical fiber's position to shift during loop laying, resulting in a decrease in the performance of the optical fiber loop product. The vision-assisted adjustment mechanism can detect and feed back to the electrical control system 3 in real time when the laying position of the optical fiber deviates. The electrical control system 3 then controls the micro motor 1-7-3 to rotate clockwise and counterclockwise, and adjusts the position of the fiber guide nozzle 1-7-2 (which is connected to the nut of the fiber guide nozzle and the screw and is limited in the circumferential direction, so it can only move laterally) through the internal lead screw to compensate for the lateral position error of the optical fiber. This ensures the positional accuracy of the optical fiber when laying it into a loop and further improves the performance of the optical fiber loop product.

[0022] Figure 5This is a schematic diagram of an expandable ring-forming unit, which mainly consists of multiple support rollers 2-2, a steel strip 2-4, support feet 2-6, a strip-shaped flexible liner 2-5, a fiber position retainer 2-3, and a ring-forming drive motor 2-1. Each support roller is rotatably supported at both ends on a pair of support feet. The multiple support rollers are arranged at a set interval. The steel strip wraps around the multiple support rollers, and its rotation is achieved by the rotation of the support rollers. The width of the strip-shaped flexible liner is smaller than the width of the steel strip, and it is fitted and adhered to the outside of the steel strip, rotating synchronously with the rotation of the steel strip.

[0023] The strip-shaped flexible liner and fiber position retainer are the core of the expandable ring-forming unit and are crucial for manufacturing large-diameter fiber optic rings. The strip-shaped flexible liner can be made of flexible materials such as polyurethane, PVC, fluororubber, and silicone rubber. The fiber position retainer is 3D printed using the same material (such as UV adhesive or epoxy resin) as the ring-forming filler used in subsequent processes. Its specific shape is as follows... Figure 6 and Figure 7 As shown, the fiber position holder is generally strip-shaped, with semi-circular grooves 2-3-1 evenly distributed along the length of the strip at its upper and lower ends. The semi-circular grooves at the upper and lower ends are staggered. The radius R of the semi-circular grooves matches the fiber diameter of the material optical fiber. Combined with the corresponding adhesive, the material optical fiber can be effectively fixed.

[0024] Combination Figure 5 , Figure 8 Before manufacturing fiber optic ring products, select appropriate sizes of steel strips, flexible inner linings, and a reasonable number of support feet and support rollers based on the diameter of the product to be manufactured. Assemble them and install ring drive motors at both ends. Then, attach several fiber position holders to the flexible inner lining in segments according to the actual size of the fiber optic ring product. Afterward, install the pre-treated fiber supply trays carrying the fiber material onto the tray shafts of fiber supply unit 1 according to the existing process. Start the device to manufacture fiber optic ring products according to the specific process plan. Figure 9 , Figure 10 , Figure 11 As shown, when manufacturing fiber optic loop products, the fiber material inside the fiber position holder needs to be adhered with adhesive. After each layer of fiber is laid, the fiber position holder is then adhered and installed on the corresponding bottom layer of fiber position holder. Then, the next layer of fiber material is laid, and so on until the product is manufactured.

[0025] After the product is completed, if Figure 12As shown, the support feet, support rollers, and steel strip are disassembled in sequence to obtain the complete optical fiber loop product 5. The strip-shaped flexible liner and fiber position retainer in the product can effectively prevent the relative displacement and deformation of the material optical fiber in the radial and axial directions, thereby ensuring product quality. Since the strip-shaped flexible liner and the material optical fiber itself are both flexible materials, the optical fiber loop product can be folded and rolled up relatively freely to reduce its volume for easy transportation. When it is transported to the place of use, the strip-shaped flexible liner is opened from the inside to form a ring structure to obtain maximum sensitivity.

[0026] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. An apparatus for fabricating ultra-large diameter optical fiber loops, characterized in that: The system includes a fiber supply unit, an expandable loop forming unit, and an electrical control system. In the fiber supply unit, the fiber material on the fiber supply tray is guided by a fiber guide pulley system and then output to the expandable loop forming unit, where a large-diameter fiber loop product is fabricated. The fiber supply unit includes a tension adjustment mechanism for adjusting the fiber supply tension and a visual auxiliary adjustment mechanism for adjusting the positional accuracy of the fiber during loop laying. The expandable loop forming unit adopts a flexible expansion combination structure matched to the diameter of the fiber loop, including multiple support rollers, a steel strip, support feet, and a strip-shaped flexible... The fiber loop includes a flexible inner liner, fiber position retainers, and a ring-forming drive motor. Each support roller is rotatably supported at both ends on a pair of support feet. Multiple support rollers are arranged at a set interval, and the number of support rollers is set according to the diameter of the fiber loop. A steel strip is wrapped around multiple support rollers and rotates with them. The flexible inner liner is fitted to the outside of the steel strip and rotates with it. The fiber position retainer located at the innermost layer of the fiber loop is fixed to the surface of the flexible inner liner. During the fabrication of the fiber loop, a certain number of fiber position retainers are set between the fibers in adjacent layers.

2. The apparatus for fabricating ultra-large diameter optical fiber loops according to claim 1, characterized in that: The fiber supply unit also includes a fiber supply worktable, a reciprocating slide, a slide drive mechanism, and a vertical support frame. The reciprocating slide is connected to the upper end of the fiber supply worktable via a linear guide rail and moves left and right reciprocally via the slide drive mechanism. The vertical support frame is vertically fixed to the upper end of the reciprocating slide and is used to install the fiber supply tray, fiber guide pulley group, tension adjustment mechanism, and visual auxiliary adjustment mechanism. The fiber supply tray is a storage tray for optical fibers and is installed on a tray shaft on the front of the vertical support. The tray shaft is driven by a fiber supply motor. The fiber guide pulley group is used to guide the optical fibers output from the fiber supply tray.

3. The apparatus for fabricating ultra-large diameter optical fiber loops according to claim 2, characterized in that: The fiber guide pulley assembly consists of four fiber guide pulleys, three of which are installed at the high end of the front of the vertical support frame at the same height, and the other fiber guide pulley is installed at the low end of the vertical support frame on the side near the expandable ring unit.

4. The apparatus for fabricating ultra-large diameter optical fiber loops according to claim 3, characterized in that: The tension adjustment mechanism is located in the space between the three fiber guide pulleys at the high end and the fiber supply tray. It consists of a tension adjustment wheel, a tension adjustment arm, and an angle encoder. One end of the tension adjustment arm is fixed to the tension adjustment shaft, which is rotatably and vertically connected to the vertical support frame. The other end of the tension adjustment arm is rotatably connected to the tension adjustment wheel. The angle encoder is coaxially fixed to the tension adjustment shaft.

5. The apparatus for fabricating ultra-large diameter optical fiber loops according to claim 4, characterized in that: The vision-assisted adjustment mechanism is located at the end of the fiber supply unit and consists of a vision sensor, a fiber guide nozzle, and a micro motor. The fiber guide nozzle is used to guide the output of the material optical fiber.

6. The apparatus for fabricating ultra-large diameter optical fiber loops according to claim 5, characterized in that: The fiber position retainer is made of the same material as the ring-filled adhesive used in subsequent processes and is manufactured by 3D printing. The fiber position retainer is strip-shaped with semi-circular grooves evenly distributed along the length of the strip at its upper and lower ends. The semi-circular grooves at the upper and lower ends are staggered, and the radius of the semi-circular grooves matches the diameter of the optical fiber.

7. The apparatus for fabricating ultra-large diameter optical fiber loops according to claim 1, characterized in that: The strip-shaped flexible liner is made of polyurethane, PVC, fluororubber, or silicone rubber.

8. A method for fabricating fiber optic loops based on the apparatus for fabricating ultra-large diameter fiber optic loops according to claim 6, characterized in that: Includes the following steps: Step 1: Select appropriate sizes of steel strips, flexible inner lining strips, and a reasonable number of support feet and support rollers according to the diameter of the fiber optic ring, assemble them, install ring drive motors at both ends, and then attach several fiber position retainers to the surface of the flexible inner lining strip in reasonable segments according to the actual size of the fiber optic ring. Step 2: Install the pre-treated fiber supply tray containing the fiber material onto the tray shaft of the fiber supply unit. After passing the two fiber guide pulleys at the front end, the tension adjustment wheel, the two fiber guide pulleys at the rear end, and the fiber guide nozzle, guide the fiber material into the semi-circular groove on one side of the fiber position holder and fix it with adhesive. Step 3: Start the ring-forming drive motor, fiber supply motor and slide table drive mechanism to make the fiber optic ring. During the process of making the fiber optic ring, the material fiber in the fiber position holder is adhered with adhesive. After each layer of fiber is laid, the fiber position holder is adhered and installed on the corresponding bottom layer of fiber position holder. Then continue to lay the next layer of material fiber, and repeat this process until the fiber optic ring is made. Step 4: After the fiber optic ring is manufactured, the support feet, support rollers, and steel strip are removed in sequence to obtain a complete fiber optic ring product.

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