Production method of anti-bending polarization maintaining optical fiber preform

Abstract

The invention discloses a production method of an anti-bending polarization-maintaining optical fiber preform, and relates to the technical field of polarization-maintaining optical fiber preforms. The method comprises the following steps that SS01, a core rod and a mother rod are manufactured through the MCVD technology, and double symmetrical holes are punched in the mother rod through a punching machine; SS02, an annular groove is formed in the outer surface of the mother rod through an annular groove machining device; SS03, stress rods are manufactured through the MCVD technology, the stress rods are ground through a centerless grinding machine, the stress rods are assembled in the symmetrical holes of the mother rod, and the stress rods are assembled in the symmetrical holes of the mother rod. SS04, high-temperature sintering is carried out, and the preform is melted and shrunk into a compact glass body. Through the design of the annular groove on the mother rod, the annular groove type sunken cladding can be formed, when the optical fiber is bent, a light field deviates towards the bending outer side, but a low-refractive-index area of the sunken cladding limits the light field from diffusing outwards and forces the light field to be more concentrated on the fiber core, so that leakage caused by bending is reduced, the bending resistance of the optical fiber is improved, and the optical fiber is suitable for being used in the optical fiber. The optical fiber gyroscope is suitable for being used as a miniaturized optical fiber gyroscope.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of polarization maintaining optical fiber preform, and particularly relates to a production method of a bending-resistant polarization maintaining optical fiber preform. BACKGROUND

[0002] The current optical fiber gyroscope is rapidly developing towards miniaturization, and this trend has strong demand in many practical application scenarios. For example, in the field of aerospace, the volume and weight requirements of internal equipment of a spacecraft are extremely strict, and a miniaturized optical fiber gyroscope can effectively reduce the load of the spacecraft and improve its performance and flexibility. In portable navigation devices and some application scenarios with strict space occupation restrictions, a miniaturized optical fiber gyroscope is indispensable.

[0003] In the miniaturization process of the optical fiber gyroscope, the bending radius of the optical fiber becomes a key parameter. When the optical fiber gyroscope develops towards miniaturization, the optical fiber needs to be wound into a smaller diameter ring, which puts higher requirements on the bending radius of the optical fiber.

[0004] Therefore, it is a problem to be solved by those skilled in the art to design a preform capable of drawing out an optical fiber with strong bending resistance. SUMMARY

[0005] The purpose of the present application is to provide a production method of a bending-resistant polarization maintaining optical fiber preform. Through the design of the annular groove on the mother rod, a ring-groove type depressed cladding can be formed. When the optical fiber is bent, the light field will shift to the outside of the bend, but the low refractive index region of the depressed cladding will limit the outward diffusion of the light field, forcing the light field to be more concentrated in the core, thereby reducing the leakage caused by bending and improving the bending resistance of the optical fiber, which is suitable for use in miniaturized optical fiber gyroscopes.

[0006] To solve the above technical problems, the present application is realized by the following technical scheme: The present application is a production method of a bending-resistant polarization maintaining optical fiber preform, comprising the following steps: SS01 A core rod and a mother rod are manufactured by the MCVD process, a double-symmetrical hole is punched on the mother rod by using a puncher, and grinding is performed by using a centerless grinding machine; SS02 An annular groove is opened on the outer surface of the mother rod by using an annular groove processing device; SS03 A stress rod is manufactured by the MCVD process, and grinding of the stress rod is performed by using a centerless grinding machine, and the stress rod is assembled in the symmetrical hole of the mother rod; SS04 High-temperature sintering is performed to make the preform shrink into a dense glass body, and the groove structure is retained; The annular groove processing device in SS03 comprises a support seat, a guide frame and a forming table; The support seat is composed of several linearly distributed arc-shaped seats, and the outer sides of the two side edges of the support seat are each provided with a ground rail; The guide frame comprises four guide rails and oppositely arranged first and second positioners, the bottom of the first positioner is provided with a sliding seat, one end of the four guide rails is fixed to the peripheral side surface of the bed of the second positioner, the peripheral side surface of the base of the first positioner is provided with four slide sleeves, the other end of the four guide rails is respectively slidably arranged in the four slide sleeves, and the clamping area of the first positioner and the second positioner is out of position with the four guide rails. The forming table comprises a group of side frames, the side frames are fixed with laser etchers towards the axis direction of the arc-shaped seats, the bottom of the two side frames is provided with a walking mechanism sliding along the ground rail, the inner side top and bottom of the side frames are each fixed with a group of guide wheels, the four groups of guide wheels on the two side frames respectively slide along the four guide rails, and the top between the two side frames is fixed by a connecting beam.

[0007] Further, the forming process of the annular groove in the SS03 comprises the following steps: SS031 The mother bar is placed on the top of several arc-shaped seats, the sliding seat is controlled to clamp and fasten the end of the mother bar through the first positioner and the second positioner, at this time the forming table is in the second positioner external area; SS032 The forming table is controlled to slowly move towards the first positioner through the walking mechanism, and the groove with an arc-shaped cross section parallel to the axis direction of the mother bar is etched on the outer surface of the mother bar through the laser etcher; SS033 The forming table is controlled to reset, and the mother bar after groove etching is moved out and transferred to the next process.

[0008] Further, the annular groove machining device in the SS03 can symmetrically open two grooves on the mother bar at a time, and if more grooves are needed, the rotation of the mother bar is controlled through the synchronous rotation of the first positioner and the second positioner.

[0009] Further, the side frame is provided with an outward convex allowance area, and the laser etcher is installed outside the allowance area.

[0010] Further, the bottom of the side frame is fixed with a fixed position of L-shaped structure, and a reinforcing rib is arranged between the inner side of the fixed position and the allowance area.

[0011] Further, the walking mechanism comprises a motor and a wheel frame, the motor is fixed in the fixed position and is out of position with the reinforcing rib, the wheel frame is fixed to the bottom surface of the fixed position, the bottom of the wheel frame is provided with a plurality of wheel bodies rolling along the ground rail, the output end of the motor is connected with one wheel body through a synchronous wheel and a synchronous belt, or a gear and rack mechanism is arranged between the motor and the ground rail.

[0012] Further, the distance between the two side frames is greater than the width of the first and second positioners, and the connecting beam is located above the first and second positioners.

[0013] Further, a tow chain slot is arranged outside the ground rail, and a tow chain is arranged in the tow chain slot.

[0014] Further, the top of the arc-shaped seat is provided with an arc-shaped opening matched with the mother rod, and the inner wall of the arc-shaped opening is provided with a soft pad.

[0015] The present application has the following advantages: 1. The annular groove type depressed cladding can be formed by the design of the annular groove on the mother rod, when the optical fiber is bent, the light field will deviate to the outside of the bending, but the low refractive index area of the depressed cladding will limit the outward diffusion of the light field, forcing the light field to be more concentrated in the core, thereby reducing the leakage caused by bending and improving the bending resistance of the optical fiber, which is suitable for the use of miniaturized optical fiber gyroscopes.

[0016] 2. The annular groove processing device can clamp the mother rod through the first and second positioners, and support the mother rod through the arc-shaped seat, thereby improving the stability of the mother rod during processing, avoiding the problem of poor stability caused by the excessive length of the preform rod, and being suitable for subsequent laser grooving, and through the design of the four guide rails, cooperating with the four guide wheels on the forming table, the forming table can be stably displaced, ensuring the stability of laser grooving and the forming effect of the groove.

[0017] Of course, implementing any product of the present application does not necessarily require all the advantages described above. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0019] Figure 1 It is a structure schematic view of the annular groove processing device of the production method of the anti-bending polarization maintaining optical fiber preform rod of the present application. In the drawings, the component list represented by each number is as follows: 1-forming table, 2-arc-shaped seat, 3-ground rail, 4-guide rail, 5-first positioner, 6-second positioner, 7-tow chain slot, 101-side frame, 102-laser etcher, 103-traveling mechanism, 104-guide wheel, 105-connecting beam, 106-giving place area, 107-fixing position, 108-stiffener, 501-sliding seat. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0021] Please refer to Figure 1 The present application is a production method of a bending-resistant polarization maintaining optical fiber preform, comprising the following steps: SS01 manufacturing a core rod and a mother rod by MCVD process, using a puncher to punch double symmetrical holes on the mother rod, and using a centerless grinding machine for grinding; SS02 opening a ring-shaped groove on the outer surface of the mother rod by a ring-shaped groove processing device; SS03 manufacturing a stress rod by MCVD process, and grinding the stress rod by a centerless grinding machine, and assembling the stress rod in the symmetrical holes of the mother rod; SS04 high-temperature sintering to make the preform shrink into a dense glass body, and retaining the groove structure; The ring-shaped groove processing device in SS03 comprises a support seat, a guide frame and a forming table 1; The support seat is composed of a plurality of linearly distributed arc-shaped seats 2, and the outer sides of the two side edges of the support seat are each provided with a ground rail 3; The guide frame comprises four guide rails 4 and oppositely arranged first and second shifters 5 and 6, the first shifter 5 is provided at the bottom with a sliding seat 501, one end of the four guide rails 4 is fixed to the peripheral side surface of the bed of the second shifter 6, the peripheral side surface of the base of the first shifter 5 is provided with four slide sleeves, the other end of the four guide rails 4 is respectively slidably arranged in the four slide sleeves, and the clamping areas of the first and second shifters 5 and 6 are staggered with the four guide rails 4; The forming table 1 comprises a group of side frames 101, the side frames 101 are fixed with laser engravers 102 facing the axis direction of the arc-shaped seats 2, the bottom of each side frame 101 is provided with a walking mechanism 103 sliding along the ground rail 3, a group of guide wheels 104 is fixed to the top and bottom of the inner side of each side frame 101, the four groups of guide wheels 104 on the two side frames 101 respectively slide along the four guide rails 4, and the top between the two side frames 101 is fixed by a connecting beam 105.

[0022] The forming process of the ring-shaped groove in SS03 comprises the following steps: SS031 placing the mother rod on the top of a plurality of arc-shaped seats 2, controlling the sliding seat 501 to clamp and fasten the end of the mother rod by the first and second shifters 5 and 6, at this time the forming table 1 is located in the external area of the second shifter 6; SS032 The forming table 1 is controlled by the walking mechanism 103 to slowly move toward the first positioner 5, and a groove with an arc-shaped cross section and parallel to the axis of the mother rod is engraved on the outer surface of the mother rod by the laser etcher 102; SS033 controls the forming table 1 to reset and remove the grooved mother rod to transfer it to the next process.

[0023] Among them, the annular groove processing device in SS03 can symmetrically open two grooves on the mother rod at a time. If more grooves are required, the rotation of the mother rod is controlled by the synchronous rotation of the first positioner 5 and the second positioner 6.

[0024] Among them Figure 1 As shown, a convex clearance area 106 is provided on the side frame 101 , and the laser etcher 102 is installed outside the clearance area 106 .

[0025] Among them Figure 1 As shown, an L-shaped fixing position 107 is fixed to the bottom of the side frame 101, and a reinforcing rib 108 is provided between the inner side of the fixing position 107 and the clearance area 106.

[0026] Among them Figure 1 As shown, the walking mechanism 103 includes a motor and a wheel frame. The motor is fixed in a fixed position 107 and is offset from the reinforcing rib 108. The wheel frame is fixed to the bottom of the fixed position 107. A plurality of wheel bodies that roll along the ground rail 3 are provided at the bottom of the wheel frame. The output end of the motor is connected to a wheel body through a synchronous wheel and a synchronous belt, or a gear rack mechanism is provided between the motor and the ground rail 3.

[0027] Among them Figure 1 As shown, the distance between the two side frames 101 is greater than the width of the first positioner 5 and the second positioner 6 , and the connecting beam 105 is located above the first positioner 5 and the second positioner 6 .

[0028] Among them Figure 1 As shown, a drag chain groove 7 is provided on the outer side of a ground rail 3, a drag chain is provided in the drag chain groove 7, and the wiring of the motor and the wiring of the laser etcher 102 are both provided in the drag chain.

[0029] Among them, the top of the arc seat 2) is provided with an arc opening that matches the mother rod, and the inner wall of the arc opening is provided with a soft cushion.

[0030] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0031] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for producing a bend-resistant polarization-maintaining optical fiber preform, characterized by: The following steps are involved: SS01 uses MCVD process to manufacture core rod and mother rod, uses punching machine to punch double symmetrical holes on the mother rod, and uses centerless grinder for grinding; SS02 uses an annular groove processing device to open an annular groove on the outer surface of the mother rod; SS03 uses MCVD process to manufacture stress rods, which are then ground using a centerless grinder and assembled into the symmetrical holes of the mother rod. SS04 is sintered at high temperature to melt the preform into a dense glass body, retaining the groove structure; The annular groove processing device in the SS03 comprises a support seat, a guide frame and a forming table (1); The support seat is composed of a plurality of linearly distributed arc-shaped seats (2), and the outer sides of both sides of the support seat are provided with ground rails (3); The guide frame includes four guide rails (4) and a first positioner (5) and a second positioner (6) arranged relatively to each other. A sliding seat (501) is provided at the bottom of the first positioner (5). One end of the four guide rails (4) is fixed to the peripheral side of the base of the second positioner (6). Four sliding sleeves are provided on the peripheral side of the base of the first positioner (5). The other ends of the four guide rails (4) are respectively slidably arranged in the four sliding sleeves. The clamping areas of the first positioner (5) and the second positioner (6) are offset from the four guide rails (4). The forming table (1) includes a group of side frames (101), a laser etcher (102) facing the axis direction of the arc seat (2) is fixed on the side frames (101), a walking mechanism (103) sliding along the ground rail (3) is provided at the bottom of the two side frames (101), a group of guide wheels (104) are fixed at the top and bottom of the inner side of the side frames (101), the four groups of guide wheels (104) on the two side frames (101) slide along the four guide rails (4) respectively, and the top between the two side frames (101) is fixed by a connecting beam (105).

2. The method for producing a bend-resistant polarization-maintaining optical fiber preform according to claim 1, wherein: The forming process of the annular groove in the SS03 includes the following steps: SS031 Place the mother rod on top of several arc-shaped seats (2), control the sliding seat (501) to clamp and tighten the end of the mother rod through the first positioner (5) and the second positioner (6), and at this time the forming table (1) is in the outer area of ​​the second positioner (6); SS032 controls the forming table (1) to slowly move toward the first positioner (5) through the walking mechanism (103), and uses the laser etcher (102) to carve a groove with an arc-shaped cross section and parallel to the axis of the mother rod on the outer surface of the mother rod; SS033 controls the forming table (1) to reset and remove the grooved mother rod to the next process.

3. The method for producing a bend-resistant polarization-maintaining optical fiber preform according to claim 2, wherein: The annular groove processing device in the SS03 can symmetrically open two grooves on the mother rod at a time. If more grooves are required, the rotation of the mother rod is controlled by the synchronous rotation of the first positioner (5) and the second positioner (6).

4. The method for producing a bend-resistant polarization-maintaining optical fiber preform according to claim 1, wherein: An outwardly convex clearance area (106) is provided on the side frame (101), and the laser etcher (102) is installed outside the clearance area (106).

5. The method for producing a bend-resistant polarization-maintaining optical fiber preform according to claim 4, wherein: An L-shaped fixing position (107) is fixed to the bottom of the side frame (101), and a reinforcing rib (108) is provided between the inner side of the fixing position (107) and the clearance area (106).

6. The method for producing a bend-resistant polarization-maintaining optical fiber preform according to claim 5, wherein: The walking mechanism (103) includes a motor and a wheel frame, wherein the motor is fixed in a fixed position (107) and is offset from the reinforcing rib (108), and the wheel frame is fixed to the bottom surface of the fixed position (107). The bottom of the wheel frame is provided with a plurality of wheel bodies that roll along the ground rail (3), and the output end of the motor is connected to a wheel body through a synchronous wheel and a synchronous belt, or a gear rack mechanism is provided between the motor and the ground rail (3).

7. The method for producing a bend-resistant polarization-maintaining optical fiber preform according to claim 1, wherein: The distance between the two side frames (101) is greater than the width of the first positioner (5) and the second positioner (6), and the connecting beam (105) is located above the first positioner (5) and the second positioner (6).

8. The method for producing a bend-resistant polarization-maintaining optical fiber preform according to claim 6, wherein: A drag chain groove (7) is provided on the outside of the ground rail (3), a drag chain is provided in the drag chain groove (7), and the wiring of the motor and the wiring of the laser etcher (102) are both provided in the drag chain.

9. The method for producing a bend-resistant polarization-maintaining optical fiber preform according to claim 1, wherein: The top of the arc-shaped seat (2) is provided with an arc-shaped opening that cooperates with the female rod, and the inner wall of the arc-shaped opening is provided with a soft cushion.

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