CN111650693A - A 3×3 single-mode micro-nano fiber coupler with controllable and continuously adjustable beam splitting ratio - Google Patents

Abstract

The invention discloses a 3×3 single-mode micro-nano optical fiber coupler with controllable and continuously adjustable beam splitting ratio. The unstretched part of one end of three micro-nano optical fibers is fixed by a first fixing member, and the unstretched part of the other end is fixed by a first fixing member. Passing through three rotatable fixed parts and each is fixed by one of the rotatable fixed parts, the central axes of the three rotatable fixed parts coincide with each other; when the three micro-nano optical fibers are in a state of being parallel to each other, the center of the three rotatable The axis is parallel to the micro-nano fiber and the distances from the cores of the three micro-nano fibers to the central axis of the rotatable fixing piece are different from each other, so that when any rotatable fixing piece is rotated, only the rotatable fixing piece can be driven. The micro-nano optical fibers are twisted; when the three micro-nano optical fibers are in the state of being parallel to each other and the coupler of the present invention is in the working state, the intersection point of the extension line of the central axis of the three rotatable fixed parts and the first fixed part is always unchanged. The method for controlling the beam splitting ratio of the present invention is various and continuously adjustable, and the application is flexible and diverse.

Description

A 3×3 single-mode micro-nano fiber coupler with controllable and continuously adjustable beam splitting ratio

technical field

The invention relates to a single-mode optical fiber coupler, in particular to a 3×3 single-mode optical fiber coupler, which can be applied in the fields of optical communication, optical signal processing, sensing systems and the like.

Background technique

As a key element in an optical network system, a single-mode fiber coupler can split optical signals from one fiber to two (or more) fibers or combine the optical signals on two (or more) fibers Passive transmission optics onto an optical fiber. Among them, the 3×3 single-mode fiber coupler is the most basic one of the single-mode fiber couplers. Since the 3×3 single-mode fiber coupler has one more coupling arm than the 2×2 coupler, the use of functional and It is more superior in signal processing and can be applied to couplers, optical switches, optical buffers, optical resonators, etc. with adjustable optical splitting ratio. The performance of the 3×3 single-mode fiber coupler directly affects the performance and application range of the optical fiber transmission system. In particular, the 3×3 single-mode fiber coupler with continuously adjustable beam splitting ratio is used in sensing detection and optical communication control systems. its special purpose.

In the prior art, the conventional process of a 3×3 single-mode fiber coupler is to stack multiple fibers together, and then melt and taper at high temperature to realize optical coupling, but the splitting ratio is fixed, and there are differences. The problem that the beam ratio is not adjustable, and it is impossible to provide a variety of controllable beam splitting ratios on one coupler, which cannot meet the application occasions where the beam splitting ratio needs to be changed, and the function is very single. In order to prepare a 3×3 single-mode fiber coupler with continuously adjustable beam splitting ratio, at present, in the application field of fiber interferometer, the solution adopted by researchers is to combine other optical components, such as 2×2 single-mode fiber coupling It can be realized by various indirect methods such as adjusting the length of the feedback fiber and changing the reflectivity of the Bragg grating. However, the applicable application fields of the above scheme are very limited, and the preparation method has high cost and complicated steps. In addition, the above solutions also cannot implement multiple control methods of the splitting ratio in one coupler, which restricts the development of the field of optical devices based on 3×3 single-mode fiber couplers.

Therefore, it is of great significance to study a 3×3 single-mode micro-nano fiber coupler with a controllable and continuously adjustable beam splitting ratio for enhancing the performance of the 3×3 single-mode fiber coupler and broadening its application fields.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a 3×3 single-mode micro-nano fiber coupler with a controllable and continuously adjustable beam splitting ratio in view of the deficiencies of the prior art, so as to overcome the inability of the prior art to couple at the same The defects of multiple controllable and continuously adjustable beam splitting ratios are realized in the device.

The technical solution adopted by the present invention to solve the above technical problems is as follows: the 3×3 single-mode micro-nano fiber coupler with a controllable and continuously adjustable beam splitting ratio of the present invention comprises three micro-nano fibers, and one end of the three micro-nano fibers is unstretched. Part of it is fixed by the first fixing piece, and the unstretched part of the other end of the three micro-nano optical fibers passes through the three rotatable fixing pieces and is fixed by one of the rotatable fixing pieces. When the central axis rotates, the central axes of the three rotatable fixed parts coincide with each other; when the three micro-nano optical fibers are in a state of being parallel to each other, the central axes of the three rotatable fixed parts are parallel to the micro-nano optical fibers and the cores of the three micro-nano optical fibers are parallel to each other. The distances to the central axis of the rotatable fixing member are different from each other, so that when any rotatable fixing member is rotated, it can only drive the micro-nano optical fiber fixed by the rotatable fixing member to twist; when the three micro-nano optical fibers are parallel to each other. In the state and when the coupler is in the working state, the intersection of the central axes of the three rotatable fixed parts and the first fixed part is always unchanged.

Further, the present invention also includes a support seat, the support seat is provided with an arc-shaped groove, the three rotatable fixing parts are respectively placed on the corresponding arc-shaped grooves, and the central axis of the arc-shaped groove coincides with the central axis of the rotatable fixing member. , so that when the rotatable fixed piece rotates around its own central axis in the arc-shaped groove, the central axes of the three rotatable fixed pieces always coincide with each other, and the central axes of the three rotatable fixed pieces and the first fixed piece The intersection point is always unchanged; in order of the distance from the rotatable fixing member to the first fixing member from near to far, the distances from the cores of the micro-nano optical fibers fixed on the three rotatable fixing members to the central axis of the rotatable fixing member are in sequence. From big to small.

Further, the first fixing member of the present invention is in the shape of an annular shape, and its inner wall is provided with a first annular groove along the circumferential direction; the three rotatable fixing members are all annular, wherein the first rotatable fixing member is The outer wall of one end is provided with a first annular protrusion matching the first annular groove along the circumferential direction, the inner wall of the other end is provided with a second annular groove along the circumferential direction, and the outer wall of one end of the second rotatable fixing member is circumferentially provided with There is a second annular protrusion matching the second annular groove in the direction, the inner wall of the other end is provided with a third annular groove along the circumferential direction, and the outer wall of one end of the third rotatable fixing member is provided with the first annular groove along the circumferential direction. The third annular protrusion is matched with the three annular grooves; the first annular protrusion is engaged with the first annular groove and can make the first rotatable fixing member rotate along the first annular groove, and the second annular protrusion is connected to the first annular groove. The second annular groove engages and enables the second rotatable fixing member to rotate along the second annular groove, and the third annular protrusion engages with the third annular groove and enables the third rotatable fixing member to rotate along the first annular groove. The three annular grooves rotate, and the distances from the cores of the micro-nano optical fibers fixed on the first rotatable fixing member, the second rotatable fixing member, and the third rotatable fixing member to the central axes of the three rotatable fixing members are sequentially given by big to small.

Further, the first fixing member of the present invention can rotate around its own central axis, and the central axis of the first fixing member coincides with the central axes of the three rotatable fixing members.

The first method for adjusting the splitting ratio of micro-nano fibers by using the coupler of the present invention is as follows: when the three micro-nano fibers are parallel to each other, firstly rotate the three rotatable fixed parts in the same direction around their central axis to the same direction. The middle waists of the three micro-nano fibers are wound together, and then any one or any two rotatable fixed parts are rotated in the original direction until the desired splitting ratio of the target micro-nano fibers is obtained.

Further, in the present invention, when the three rotatable fixing members rotate in the same direction around their central axis at the same time, the first fixing member rotates around its central axis in the opposite direction to the rotatable fixing member, and the first fixing member rotates in the opposite direction to the rotatable fixing member. The central axis coincides with the central axes of the three rotatable fixing members.

The second method for adjusting the splitting ratio of micro-nano fibers by using the coupler of the present invention is as follows: when the three micro-nano fibers are parallel to each other, firstly rotate the three rotatable fixed parts in the same direction around their central axis to the same direction. The middle waists of the three micro-nano optical fibers are wound together, and then the three rotatable fixing members continue to rotate at least half a turn in the original direction, and then either or any two rotatable fixing members are rotated in the original or reverse direction until the target is obtained. The desired splitting ratio of micro-nano fibers.

Further, in the present invention, when the three rotatable fixing members rotate in the same direction around their central axis at the same time, the first fixing member rotates around its central axis in the opposite direction to the rotatable fixing member, and the first fixing member rotates in the opposite direction to the rotatable fixing member. The central axis coincides with the central axes of the three rotatable fixing members.

The third method for adjusting the splitting ratio of micro-nano fibers by using the coupler of the present invention is as follows: when the three micro-nano fibers are in parallel with each other, first rotate any two rotatable fixed parts in the same direction around their central axis at the same time. The middle waist sections of the two micro-nano optical fibers fixed by it are wound together, and then continue to rotate any one or any two of the three rotatable fixed parts around its central axis according to the original direction until the target micro-nano optical fiber is obtained. The desired splitting ratio of the fiber.

Further, in the present invention, when the three rotatable fixing members rotate in the same direction around their central axis at the same time, the first fixing member rotates around its central axis in the opposite direction to the rotatable fixing member, and the first fixing member rotates in the opposite direction to the rotatable fixing member. The central axis coincides with the central axes of the three rotatable fixing members.

Compared with the prior art, the present invention has the advantages of:

(1) The preparation process of the coupler is simple, the preparation materials are simplified, and the preparation cost is low;

(2) The splitting ratio of the coupler can be controlled and adjusted in a variety of ways;

(3) The splitting ratio of the coupler is continuously adjustable;

(4) The preparation method of the coupler makes it possible to realize the control of multiple beam splitting ratios at the same time on the same coupler, which is more flexible and diverse in application;

(5) The number of micro-nano fibers used in the coupler can be expanded to N, so that the coupler becomes an N*N device with N input ends and N output ends, which has strong scalability.

Description of drawings

The technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a schematic structural diagram of the first embodiment of the coupler of the present invention when it is in an initial state;

2 is a diagram showing the mutual positional relationship between three rotatable fixing members and the micro-nano optical fibers fixed thereon in the first embodiment of the coupler of the present invention;

3 is a schematic structural diagram of three rotatable fixing members in FIG. 2;

FIG. 4 is a schematic structural diagram of the second embodiment of the coupler of the present invention when it is in an initial state;

5 is a schematic diagram of the internal structure of the first fixing member in FIG. 4;

6 is a schematic structural diagram of three rotatable fixing members in FIG. 4;

7 is a schematic diagram of the installation relationship between the first fixing member and the three rotatable fixing members in FIG. 4;

8 is a schematic diagram of the positions of the micro-nano optical fibers fixed by the three rotatable fixing members in the second embodiment of the coupler of the present invention;

9 is a schematic diagram of the state when the middle waist sections of the three micro-nano optical fibers are just wound together after using the second embodiment of the coupler of the present invention to simultaneously rotate the three rotatable fixing members in the same direction;

Figure 10 is a schematic diagram of the state in which the middle waists of the three micro-nano optical fibers are wound together after the three rotatable fixing members in Figure 9 are rotated simultaneously in the original direction;

In the figure: 1- the first micro-nano fiber, 2- the second micro-nano fiber, 3- the third micro-nano fiber, A- the core of the first micro-nano fiber, B- the second micro-nano fiber core, C - Core of the third micro-nano fiber, Q-central axis, 1M- the middle waist of the first micro-nano fiber, 2M- the middle waist of the second micro-nano fiber, 3M- the middle waist of the third micro-nano fiber , 4-the first fixing piece, 41-annular groove 31-the first rotatable fixing piece, 32-the second rotatable fixing piece, 33-the third rotatable fixing piece, 71-annular protrusion, 72-annular concave Slot, 5-support base, 6-arc-shaped slot, 311-inner wall of the first rotatable fixing piece, 321-inner wall of the second rotatable fixing piece, 331-inner wall of the third rotatable fixing piece.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1, FIG. 4, FIG. 9 and FIG. 10, the 3×3 single-mode micro-nano fiber coupler with controllable and continuously adjustable beam splitting ratio of the present invention includes three micro-nano fibers 1, 2, 3, three micro-nano fibers 1, 2, 3 The unstretched part of one end of the nano-fiber is fixed by the first fixing member 4, and the unstretched part of the other end of the three micro-nano optical fibers passes through the three rotatable fixing parts 31, 32, 33 and is rotatable by one of them. The fixing pieces are fixed, each rotatable fixing piece can rotate around its own central axis, and the central axes of the three rotatable fixing pieces 31, 32, and 33 coincide with each other; , the central axes of the three rotatable fixing members 31, 32, 33 are parallel to the micro-nano fibers and the distances from the cores of the three micro-nano fibers to the central axis of the rotatable fixing members are different from each other, so that when any one of the rotatable fixing members is rotatably fixed When the component is rotated, it can only drive the micro-nano optical fibers fixed by the rotatable fixing member to twist; when the three micro-nano optical fibers 1, 2, 3 are in a state of being parallel to each other and when the coupler of the present invention is in a working state, the three can be rotated. The intersections of the central axes of the rotary fixing members 31, 32, and 33 and the first fixing member are always unchanged.

In the present invention, the three micro-nano optical fibers 1, 2, and 3 can be prepared by using common commercial 1550 nm single-mode optical fibers to simultaneously melt and taper under the same preparation parameter setting. A glass slide can be used as the first fixing member 4, and the unstretched part of one end of the three micro-nano optical fibers 1, 2, and 3 can be fixed on the first fixing member 4 with a foam fixing glue, and three commercial high-precision optical fibers can be used. The fiber rotator is used as three rotatable fixing parts 31, 32, 33, and the other end unstretched part of the three micro-nano optical fibers 1, 2, 3 can be fixed on the rotatable fixing parts 31, 32, 33 respectively by using fixing glue .

1 to 3 show a first embodiment of the present invention. In this embodiment, the present invention also includes a support base 5, an arc-shaped groove 6 is provided on the support base 5, and the three rotatable fixing members 31, 32, 33 are respectively placed on the corresponding arc-shaped groove 6, and the arc-shaped groove The central axis of 6 coincides with the central axis of the rotatable fixing piece, so that when the rotatable fixing piece rotates around its central axis in the arc-shaped slot 6, the central axes of the three rotatable fixing pieces 31, 32, 33 are always coincide with each other, and the intersection point of the extension line of the central axis of the three rotatable fixing members 31 , 32 , 33 and the first fixing member 4 is always unchanged. As shown in FIG. 1 , the distances between the rotatable fixing members 31, 32, 33 and the first fixing member 4 are from near to far, and the unstretched part of one end of the three micro-nano optical fibers 1, 2, and 3 is fixed on the first fixing member. 4 on. As shown in FIG. 2 and FIG. 3 , the rotatable fixing members 31 , 32 , and 33 are preferably annular, and the unstretched part of the other end of the micro-nano optical fiber 1 is fixed on A of the inner wall 311 of the rotatable fixing member 31 by fixing glue. , the unstretched part of the other end of the micro-nano optical fiber 2 is fixed at the position B of the inner wall 321 of the rotatable fixing member 32 by the fixing glue, and the unstretched part of the other end of the micro-nano optical fiber 3 is fixed on the rotatable fixing member through the fixing glue. At the position C of the inner wall 331 of 33, the distances AQ, BQ, and CQ from the cores of the micro-nano fibers 1, 2, and 3 to the central axis of the rotatable fixing member are in turn from large to small, so that when any rotatable fixing member is rotated , it can only drive the micro-nano optical fibers fixed by the rotatable fixing member to twist.

In addition, the first fixing member 4 can be fixed or can be rotated around its own central axis. As shown in FIG. 1 , the outer contour of the first fixing member 4 is circular, and a support base 5 with an arc-shaped groove 6 is arranged below it. The central axis of the arc-shaped groove 6 is connected to the rotatable fixing members 31, 32, The central axis of 33 coincides, and the first fixing member 4 is placed in the arc-shaped groove 6, then the first fixing member 4 can rotate around its own central axis, and its central axis is connected with the three rotatable fixing members 31, 32, 33. The central axes of the s always coincide with each other. No matter when the three micro-nano optical fibers 1, 2, 3 are in a state of being parallel to each other, or when the coupler is in a working state, rotate the three rotatable fixing pieces 31, 32, 33 and the first fixing piece 4 around its center When the axes rotate, the intersection of the central axes of the three rotatable fixing members 31 , 32 , and 33 and the first fixing member 4 is always unchanged.

4 to 10 show the second embodiment of the present invention, wherein the first fixing member 4 is in the shape of a circular ring, and its inner wall is provided with a first annular groove 41 along the circumferential direction; three rotatable fixing members 31 , 32 and 33 are all annular, wherein the outer wall of one end of the first rotatable fixing member 31 is provided with a first annular protrusion 71 matching the first annular groove 41 along the circumferential direction, and the inner wall of the other end is along the circumferential direction. A second annular groove 72 is provided in the circumferential direction, the outer wall of one end of the second rotatable fixing member 32 is provided with a second annular protrusion 71 that matches the second annular groove 72 along the circumferential direction, and the inner wall of the other end is provided along the circumferential direction. A third annular groove 72 is provided in the direction, and an outer wall of one end of the third rotatable fixing member 33 is provided with a third annular protrusion 71 matching the third annular groove 72 along the circumferential direction. As shown in FIGS. 4 , 7 , 9 and 10 , the distances between the first rotatable fixing member 31 , the second rotatable fixing member 32 , the third rotatable fixing member 33 and the first fixing member 4 are in order from near to Far. The first annular protrusion 71 is engaged with the first annular groove 41 and can make the first rotatable fixing member 31 rotate along the first annular groove 41 . The second annular protrusion 71 is engaged with the second annular groove 72 and can make the second rotatable fixing member 32 rotate along the second annular groove 72 . The third annular protrusion 71 is engaged with the third annular groove 72 and can make the third rotatable fixing member 33 rotate along the third annular groove 72 . One end of the three micro-nano optical fibers 1 , 2 , and 3 is not stretched and fixed on the first fixing member 4 . As shown in FIG. 8 , the three rotatable fixing members 31 , 32 and 33 are preferably annular, and the unstretched part of the other end of the micro-nano optical fiber 1 is fixed on the inner wall 311 of the first rotatable fixing member 31 by fixing glue. At A, the unstretched part of the other end of the micro-nano optical fiber 2 is fixed at the position B of the inner wall 321 of the second rotatable fixing member 32 by fixing glue, and the unstretched part of the other end of the micro-nano optical fiber 3 is fixed by the fixing glue on the first At the position C of the inner wall 331 of the three rotatable fixing members 33, the distances AQ, BQ, and CQ from the cores of the micro-nano optical fibers 1, 2, and 3 to the central axis of the rotatable fixing member are in turn from large to small, so that when any one can be When the rotating fixing member is rotated, it can only drive the micro-nano optical fibers fixed by the rotatable fixing member to twist.

Similarly, in the second embodiment of the present invention, the first fixing member 4 can be fixed or can be rotated around its own central axis. When the first fixing member 4 rotates around its central axis, its central axis and the central axes of the three rotatable fixing members 31 , 32 and 33 always coincide with each other. No matter when the three micro-nano optical fibers 1, 2, 3 are in a state of being parallel to each other, or when the coupler is in a working state, rotate the three rotatable fixing pieces 31, 32, 33 and the first fixing piece 4 around its center When the axes rotate, the intersection of the central axes of the three rotatable fixing members 31 , 32 , and 33 and the first fixing member 4 is always unchanged.

The three micro-nano optical fibers of the present invention can be prepared by using common commercial 1550 nm single-mode optical fibers to simultaneously melt and taper with the same preparation parameters.

和

连续变化的情况，直至得到目标微纳光纤的所需分束比时停止旋转可旋转固定件。当三个可旋转固定件31、32、33同时绕着自身的中心轴线同方向旋转的同时，第一固定件4亦可绕着自身的中心轴线朝与可旋转固定件相反的方向旋转，此时第一固定件4的中心轴线与三个可旋转固定件31、32、33的中心轴线重合。When using the coupler of the present invention, the micro-nano fiber 1 can be selected as the straight-through micro-nano fiber, and the micro-nano fiber 2 and the micro-nano fiber 3 are selected as the coupling fibers. As shown in Figure 1, Figure 4, Figure 9 and Figure 10, input a light source with a certain power Pin to the left port of the micro-nano fiber 1, and the right port of the micro-nano fiber 1 can be monitored by the power detectors D1, D2, and D3 respectively. The output power Pout1, the output power Pout2 of the right port of the micro-nano fiber 2, and the output power Pout3 of the right port of the micro-nano fiber 3. As shown in Figures 1 and 4, when the coupler of the present invention is in the initial state, the three micro-nano fibers 1, 2, and 3 are parallel to each other, and the middle waist sections 1M, 2M, and 3M are also in a state of being parallel to each other. Because the middle waist sections 1M, 2M, and 3M of the three micro-nano fibers are spatially parallel to each other and do not contact each other, and there is no winding relationship, at this time, the right port of the micro-nano fiber 2 and the right port of the micro-nano fiber 3 have no output power value. . Then, the winding length of the middle waist section of the corresponding micro-nano fiber is adjusted by rotating the corresponding rotatable fixing member, thereby changing the beam splitting ratio of the micro-nano fiber. While rotating the rotatable fixture, the beam splitting ratio can be observed in real time through the power detectors D1, D2, and D3 respectively.

and

Continuously changing the situation, until the desired splitting ratio of the target micro-nano fiber is obtained, stop rotating the rotatable fixing member. When the three rotatable fixing members 31, 32, 33 rotate in the same direction around their central axis at the same time, the first fixing member 4 can also rotate around its central axis in the opposite direction to the rotatable fixing member. When the central axis of the first fixing member 4 coincides with the central axes of the three rotatable fixing members 31 , 32 and 33 .

The method for adjusting the splitting ratio of the micro-nano fiber by using the coupler of the present invention is further described below.

和

连续变化的情况，直至得到目标微纳光纤的所需分束比时停止旋转可旋转固定件。The first method is: when the three micro-nano fibers 1, 2, and 3 are parallel to each other, first rotate the three rotatable fixing members 31, 32, 33 in the same direction around their central axis to the three micro-nano fibers. The middle waist sections 1M, 2M, and 3M of the optical fibers are wound together (see Figure 9), and then any one or any two rotatable fixing pieces are rotated in the original direction, thereby adjusting the winding of the middle waist sections of the three micro-nano fibers. length to change the splitting ratio of micro-nano fibers. Real-time observation of beam splitting ratio through power detectors D1, D2, D3

and

Continuously changing the situation, until the desired splitting ratio of the target micro-nano fiber is obtained, stop rotating the rotatable fixing member.

和

连续变化的情况，直至得到目标微纳光纤的所需分束比时停止旋转可旋转固定件。The second method is: when the three micro-nano fibers 1, 2, and 3 are in parallel with each other, first rotate the three rotatable fixing members 31, 32, 33 in the same direction around their central axis to the three micro-nano fibers. The middle waist sections 1M, 2M, and 3M of the optical fiber are wound together (see Figure 9), and then the three rotatable fixing members 31, 32, 33 continue to rotate at least half a turn in the original direction (see Figure 10), and then continue to rotate in the original direction. Or rotate either or both of the rotatable fixtures in the opposite direction. Real-time observation of beam splitting ratio through power detectors D1, D2, D3

and

Continuously changing the situation, until the desired splitting ratio of the target micro-nano fiber is obtained, stop rotating the rotatable fixing member.

和

连续变化的情况，直至得到目标微纳光纤的所需分束比时停止旋转可旋转固定件。The third method is: when the three micro-nano fibers 1, 2, and 3 are parallel to each other, first rotate any two rotatable fixing members in the same direction around their central axis to the two micro-nano fibers fixed by them in the same direction. The middle waist sections of the nanofiber are wound together (not shown in the figure), and then any one or two of the three rotatable fixing members are rotated around their central axis in the original direction. Real-time observation of beam splitting ratio through power detectors D1, D2, D3

and

Continuously changing the situation, until the desired splitting ratio of the target micro-nano fiber is obtained, stop rotating the rotatable fixing member.

According to actual work requirements, the splitting ratio of the present invention can be adjusted according to the above three methods to obtain the following three results: the splitting ratios of the three micro-nano fibers are different from each other; If the ratio is the same, the splitting ratio of the other micro-nano fiber is different; the splitting ratio of the three micro-nano fibers is the same.

In conclusion, the coupler of the present invention realizes controllable and continuously adjustable multiple beam splitting ratios in the same coupler. The control precision of the beam splitting ratio of the present invention is determined by the rotation precision of the rotatable fixing member, and the ratio between the three beam splitting ratios is determined by the number of rotations.

Claims (10)

1. A 3×3 single-mode micro-nano fiber coupler with a controllable and continuously adjustable beam splitting ratio is characterized in that: it comprises three micro-nano fibers, and the unstretched part of one end of the three micro-nano fibers is fixed by the first The unstretched part of the other end of the three micro-nano optical fibers passes through the three rotatable fixed parts and is fixed by one of the rotatable fixed parts, and each rotatable fixed part can rotate around its own central axis, and the three The central axes of the three rotatable fixing members are coincident with each other; when the three micro-nano optical fibers are in a state of being parallel to each other, the central axes of the three rotatable fixing members are parallel to the micro-nano optical fibers and the cores of the three micro-nano optical fibers are connected to the rotatable fixing member The distances of the central axes of the s are different from each other, so that when any rotatable fixing member is rotated, it can only drive the micro-nano optical fibers fixed by the rotatable fixing member to twist; when the three micro-nano optical fibers are in a mutually parallel state and the coupling When the device is in a working state, the intersection of the central axes of the three rotatable fixed parts and the first fixed part is always unchanged. 2. The coupler according to claim 1, characterized in that it further comprises a support seat, the support seat is provided with an arc-shaped groove, and the three rotatable fixing parts are respectively placed on the corresponding arc-shaped grooves, and the The central axis coincides with the central axis of the rotatable fixed piece, so that when the rotatable fixed piece rotates around its own central axis in the arc-shaped groove, the central axes of the three rotatable fixed pieces always coincide with each other, and the three rotatable fixed pieces always coincide with each other. The intersection of the central axis of the fixing piece and the first fixing piece is always the same; according to the order of the distance between the rotatable fixing piece and the first fixing piece from near to far, the cores of the micro-nano optical fibers fixed on the three rotatable fixing pieces The distances to the central axis of the rotatable fixing member are in descending order. 3 . The coupler according to claim 1 , wherein the first fixing member is annular, and the inner wall thereof is provided with a first annular groove along the circumferential direction; the three rotatable fixing members are all annular, Wherein, the outer wall of one end of the first rotatable fixing member is provided with a first annular protrusion matching the first annular groove along the circumferential direction, and the inner wall of the other end is provided with a second annular groove along the circumferential direction, and the second annular groove is arranged along the circumferential direction. The outer wall of one end of the rotating fixing piece is provided with a second annular protrusion matching the second annular groove along the circumferential direction, the inner wall of the other end is provided with a third annular groove along the circumferential direction, and one end of the third rotatable fixing piece The outer wall is provided with a third annular protrusion that matches the third annular groove along the circumferential direction; the first annular protrusion is engaged with the first annular groove and can make the first rotatable fixing member along the The groove rotates, the second annular protrusion is engaged with the second annular groove and can make the second rotatable fixing member rotate along the second annular groove, and the third annular protrusion is engaged with the third annular groove and can make the second rotatable fixing member rotate along the second annular groove. The third rotatable fixing member rotates along the third annular groove, and the cores of the micro-nano optical fibers fixed on the first rotatable fixing member, the second rotatable fixing member, and the third rotatable fixing member respectively reach the three rotatable The distances between the central axes of the fixing pieces are in descending order. 4. The coupler according to any one of claims 1 to 3, wherein the first fixing member is rotatable around its own central axis, and the central axis of the first fixing member and the three rotatable The central axes of the fixing pieces are coincident. 5. A method for adjusting the splitting ratio of micro-nano fibers by using the coupler according to any one of claims 1 to 3, characterized in that: when the three micro-nano fibers are parallel to each other, three rotatable and fixed fibers are first At the same time, the component rotates around its central axis in the same direction until the middle waist sections of the three micro-nano fibers are wound together, and then continue to rotate any one or any two rotatable fixed parts in the original direction until the desired fraction of the target micro-nano fiber is obtained. beam ratio. 6. The method according to claim 5, characterized in that: when the three rotatable fixing members rotate in the same direction around their central axis at the same time, the first fixing member faces the rotatable fixing member around its own central axis. Rotating in the opposite direction, the central axis of the first fixing member coincides with the central axes of the three rotatable fixing members. 7. A method for adjusting the splitting ratio of micro-nano fibers using the coupler according to any one of claims 1 to 3, characterized in that: when the three micro-nano fibers are parallel to each other, three rotatable and fixed fibers are first At the same time, the three rotatable fixed parts are rotated in the same direction around their central axis until the middle waists of the three micro-nano optical fibers are wound together, and then the three rotatable fixed parts continue to be rotated in the original direction for at least half a turn, and then rotated in the original direction or in the opposite direction. One or any two rotatable fixtures until the desired splitting ratio of the target micro-nano fiber is obtained. 8. The method according to claim 7, characterized in that: when the three rotatable fixing members rotate in the same direction around their own central axis at the same time, the first fixing member faces the rotatable fixing member around its own central axis. Rotating in the opposite direction, the central axis of the first fixing member coincides with the central axes of the three rotatable fixing members. 9. A method for adjusting the splitting ratio of micro-nano fibers using the coupler according to any one of claims 1 to 3, characterized in that: when the three micro-nano fibers are parallel to each other, any two rotatable fibers are first At the same time, the fixing piece rotates around its central axis in the same direction until the middle waist sections of the two micro-nano optical fibers fixed by it are wound together, and then continue to rotate any one or any two of the three rotatable fixing pieces in the original direction. Rotate around its own central axis until the desired splitting ratio of the target micro-nano fiber is obtained. 10. The method according to claim 9, characterized in that: when the three rotatable fixing members rotate in the same direction around their own central axis at the same time, the first fixing member faces towards the rotatable fixing member around its own central axis. Rotating in the opposite direction, the central axis of the first fixing member coincides with the central axes of the three rotatable fixing members.

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