CN213934305U

CN213934305U - Coupling structure of SESAM and optic fibre

Info

Publication number: CN213934305U
Application number: CN202022948580.0U
Authority: CN
Inventors: 郑建奎; 崔索超; 陈炯
Original assignee: 717th Research Institute of CSIC
Current assignee: 717th Research Institute of CSIC
Priority date: 2020-12-07
Filing date: 2020-12-07
Publication date: 2021-08-10
Anticipated expiration: 2030-12-07

Abstract

The utility model relates to a coupling structure of SESAM (semiconductor acceptable absorbent mirror) and optic fibre, include: the optical fiber optical path switching device comprises an optical fiber optical path switching device, a plug, an SESAM mounting seat and a multi-shaft mounting frame; the plug comprises micropores, and the optical fiber penetrates from one end face of the plug to the other end face of the plug through the micropores; the other end face of the plug and the mirror face end of the SESAM7 are sealed in a closed space; the SESAM is arranged on the SESAM mounting seat, the multi-shaft mounting rack clamps the SESAM mounting seat to adjust the relative distance and angle between the mirror end of the SESAM and the other end face of the plug, and each working point of the SESAM corresponds to each optical fiber after passing through the plug; the switching work of the SESAM is realized through the switching of a plurality of optical fibers, the utilization rate of the SESAM is improved, the service life of the SESAM is obviously prolonged, and the maintenance cost of the laser is reduced; the coupling mode has the advantages of simple structure, feasible operation, low cost and compact volume, realizes the full optical fiber and the point changing of the SESAM, and is very favorable for the batch production of the optical fiber ultrafast laser.

Description

Coupling structure of SESAM and optic fibre

Technical Field

The utility model relates to a laser technical field especially relates to a coupling structure of SESAM and optic fibre.

Background

The ultrafast fiber laser generated by using the SESAM passive mode locking can generate ultrashort pulses of picoseconds to femtosecond magnitude, and is the mainstream technical scheme of the current ultrafast oscillator. Compared with the prior pure semiconductor saturable absorber, the SESAM has the advantages of convenient self-starting, simple use, small insertion loss and the like, and is widely used.

However, although the SESAM has achieved great success in the field of ultrafast lasers, it still fails to completely solve the disadvantages of low damage threshold, easy damage and short lifetime, which is very disadvantageous for its application in some fields, for example, in industrial ultrafast lasers requiring long-time continuous operation, in order to avoid the damage to the SESAM caused by long-time operation, some manufacturers use a long-strip-shaped SESAM for mode locking in their solid ultrafast oscillators, adjust the reflection point of the oscillation-starting laser on the SESAM by a pair of electrically controlled adjustable mirror frames according to the operation time of a single point on the surface of the SESAM, and continuously change the point on the long-strip-shaped SESAM to prolong the service life of the SESAM, thereby ensuring the lifetime of the ultrafast laser.

However, for the fiber ultrafast oscillator, the point changing by the electrically controlled mirror bracket is difficult to be realized similarly to the solid ultrafast oscillator, and the coupling mode and the packaging method of the common fiber ultrafast oscillator to the SESAM are as follows:

(1) the SESAM is adhered to a ceramic inserting core of the optical fiber jumper wire joint through glue, then the SESAM is pushed to the heat sink through screwing the optical fiber jumper wire joint, and indium foil is generally placed in the middle of the SESAM or heat-conducting glue is coated on the SESAM to enhance heat conduction. The method is simple to operate, can realize full optical fiber and has good anti-imbalance capacity, but the point can not be changed and the humidity can not be controlled, and is the main mode of the SESAM packaged by the current optical fiber ultrafast oscillator.

(2) The SESAM is welded or bonded on the heat sink, and then the coupling between the optical fiber and the SESAM is realized through the lens group. This method can be changed over many times by readjusting the position of the SESAM, but the adjustment is very complicated, the resistance to detuning is poor and the threshold value of the start-up is high, and therefore it is rarely used in practice.

The first method described above primarily addresses the use of SESAMs in fiber ultrafast oscillators, but the lifetime is still short, mainly for three reasons:

(1) first, in relation to the properties of the SESAM material itself, during the self-initiated mode-locking of the SESAM, a Q-switching phase occurs before the stable mode-locking phase, which generates a large pulse with a high peak power in the cavity, which can cause the SESAM to be damaged when reflected from the SESAM surface.

(2) Secondly, related to the heat dissipation of the SESAM, the reflectivity of the SESAM to the laser in the resonant cavity cannot reach 100%, so that part of the laser is absorbed and converted into heat, the heat is accumulated to cause the temperature rise of the SESAM, and the SESAM is damaged if the heat dissipation is not timely.

(3) The SESAM is composed of a multilayer structure and an antireflection film on the surface, and when the humidity of the environment is too high, moisture in air is easily absorbed to cause performance reduction or failure of the functional layer and the coating layer.

SUMMERY OF THE UTILITY MODEL

The utility model discloses to the technical problem who exists among the prior art, provide a coupling structure of SESAM and optic fibre, solve among the prior art SESAM problem that the life-span is short in the application of optic fibre ultrafast oscillator.

The utility model provides an above-mentioned technical problem's technical scheme as follows: a SESAM to fiber coupling structure comprising: the optical fiber 3, the SESAM7, the optical fiber optical path switching device 2 and the plug 4;

the optical fiber light path switching device 2 comprises an optical fiber light path at one end and at least one optical fiber light path at the other end, and switches the optical fiber light path at one end to be communicated with the optical fiber light path at any one of the other ends; at least one optical fiber light path at the other end is respectively inserted into the plug 4 through the corresponding optical fibers 3;

the plug 4 includes respective micro-holes through which the optical fibers 3 pass from one end face to the other end face of the plug 4;

the other end face of the plug 4 and the mirror end of the SESAM7 are enclosed in a closed space; the respective operating points of the SESAM7 correspond to the respective positions of the optical fibers 3 after passing through the plug 4.

The utility model has the advantages that: the utility model provides a coupling structure of SESAM and optic fibre can be under the condition of not mechanical regulation SESAM position, through the relative distance of multiaxis mounting bracket adjustment SESAM and optic fibre and angle, then realize the work of changing points of SESAM through the switching of many optic fibres, improved the utilization ratio of SESAM, obviously prolonged the life of SESAM, reduced the maintenance cost of laser instrument; the SESAM and the optical fiber end face are arranged in a closed environment, dry nitrogen or air can be filled in the closed environment, the SESAM is ensured not to be interfered by moisture, no condensed water exists on the optical fiber end face and the surface of the SESAM, and the stability of the SESAM is further improved; the coupling mode has the advantages of simple structure, feasible operation, low cost and compact volume, realizes the full optical fiber and the point changing of the SESAM, and is very favorable for the batch production of the optical fiber ultrafast laser.

On the basis of the technical scheme, the utility model discloses can also do following improvement.

Further, the SESAM7 is mounted on the SESAM mounting seat 9, and the multiaxial mounting frame 12 clamps the SESAM mounting seat 9 to adjust the relative distance and angle between the mirror end of the SESAM7 and the other end surface of the plug 4, so that each working point of the SESAM7 corresponds to the position of each optical fiber 3 passing through the plug 4.

Further, when the optical fiber 3 is inserted into the micro hole of the plug 4, the curing adhesive is arranged in the micro hole, and the coating layer is stripped from the part of the optical fiber 3 inserted into the micro hole.

Further, after the optical fiber 3 is inserted into the micro hole, the curing glue is cured, and then the optical fiber 3 penetrates through the other end face of the plug 4 to be ground and polished into a flat end face.

Further, the plug 4 is made of ceramic or glass.

Further, a fiber laser 1 is arranged on one side of the optical fiber light path switching device 2;

the laser emitted from the optical fiber laser 1 is input to an optical fiber path at one end of the optical fiber path switching device 2.

Further, the SESAM mounting seat 9 is a convex structure, the SESAM7 is fixedly mounted on the upper surface of the convex part of the SESAM mounting seat 9 through an adhesive 8, and the adhesive 8 is a heat-conducting glue or a welding agent.

Further, the coupling structure further comprises a glass tube 6;

said plug 4 is disposed on one side of the interior of said glass tube 6, said SESAM7 and boss portion are disposed on the other side of the interior of said glass tube 6 after said SESAM7 is mounted on top of the boss portion of said SESAM mount 9;

the plug 4 and the protruding part of the SESAM mounting seat 9 are sealed with the inner wall of the glass tube 6 by a sealant.

Further, the SESAM mounting base 9 is further provided with a TEC10 for controlling the temperature of the SESAM 7.

Further, the TEC10 is connected to a heat sink 11.

The beneficial effect of adopting the further scheme is that: the SESAM and the end face of the optical fiber are arranged in a closed environment through the glass tube, the glass tube wraps and seals the plug and the convex part of the mounting seat by sealant, dry nitrogen or air can be filled into the glass tube, the SESAM is ensured not to be interfered by moisture, no condensed water exists on the end face of the optical fiber and the surface of the SESAM, and the stability of the SESAM is further improved; the temperature of the SESAM can be controlled through the TEC and the heat sink, so that the heat dissipation performance of the SESAM is obviously improved, and the service life of the SESAM is prolonged.

Drawings

Fig. 1 is a schematic structural diagram of a coupling structure of an SESAM and an optical fiber according to an embodiment of the present invention;

fig. 2 is an enlarged schematic view of the connector end face of the first embodiment of the coupling structure of an SESAM and an optical fiber according to the present invention after being ground;

fig. 3 is an enlarged schematic view of a second embodiment of a coupling structure of an SESAM and an optical fiber according to the present invention after the plug end face is ground;

fig. 4 is an enlarged schematic view of the connector end face of the third embodiment of the coupling structure of the SESAM and the optical fiber according to the present invention after being ground;

in the drawings, the components represented by the respective reference numerals are listed below:

1. the optical fiber laser device comprises an optical fiber laser device body 2, an optical fiber light path switching device body 3, an optical fiber 3-01, a first optical fiber 3-02, a second optical fiber 3-03, a third optical fiber 3-04, a fourth optical fiber 3-05, a fifth optical fiber 4, a plug 5, sealant 6, a glass tube 7, an SESAM 8, an adhesive, 9, sealant 9, an SESAM mounting seat 10, a TEC 11, a heat sink 12 and a multi-axis adjusting frame.

Detailed Description

The principles and features of the present invention are described below in conjunction with the following drawings, the examples given are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

In view of the current main coupling mode and encapsulation method for the SESAM in the fiber ultrafast oscillator, which cannot satisfy the requirement of long-time continuous operation, as shown in fig. 1, the embodiment of the present invention provides a structural schematic diagram of a coupling structure of the SESAM and the fiber, as can be seen from fig. 1, the present invention provides a coupling structure of the SESAM and the fiber, which includes: optical fiber 3, SESAM7, fiber optic switching apparatus 2, and plug 4.

The optical fiber optical path switching device 2 includes one optical fiber optical path at one end and at least one optical fiber optical path at the other end, and switches the one optical fiber optical path at one end to communicate with the optical fiber optical path at any one of the other ends. At least one optical fiber light path at the other end is respectively inserted into the plug 4 through the corresponding optical fibers 3.

The plug 4 includes respective micro holes through which the optical fibers 3 pass from one end face to the other end face of the plug 4.

The other end face of the plug 4 is closed in a closed space with the mirror end of the SESAM 7.

The respective operating points of SESAM7 correspond to the positions of the respective optical fibers 3 after passing through plug 4.

The utility model provides a coupling structure of SESAM and optic fibre can be under the condition of not mechanical regulation SESAM position, through the relative distance of multiaxis mounting bracket adjustment SESAM and optic fibre and angle, then realize the work of changing points of SESAM through the switching of many optic fibres, improved the utilization ratio of SESAM, obviously prolonged the life of SESAM, reduced the maintenance cost of laser instrument; the SESAM and the optical fiber end face are arranged in a closed environment, dry nitrogen or air can be filled in the closed environment, the SESAM is ensured not to be interfered by moisture, no condensed water exists on the optical fiber end face and the surface of the SESAM, and the stability of the SESAM is further improved; the coupling mode has the advantages of easy point changing, simple structure, feasible operation, small debugging difficulty, low cost, compact volume, excellent environment of the SESAM and convenient heat dissipation, realizes the full optical fiber and point changing of the SESAM, greatly prolongs the service life of the SESAM, meets the aim of industrial large-scale production, and is very favorable for the batch production of the optical fiber ultrafast laser.

Example 1

Embodiment 1 provided by the utility model is that the utility model provides a pair of the coupling structure's of SESAM and optic fibre embodiment, can know from FIG. 1, this coupling structure's embodiment includes: the optical fiber optical path switching device comprises an optical fiber optical path switching device 2, an optical fiber 3, a plug 4, a glass tube 6, a SESAM7, an adhesive 8, a SESAM mounting base 9, a TEC (thermoelectric cooler) 10, a heat sink 11 and a multi-axis mounting frame 12.

The optical fiber light path switching device 2 comprises an optical fiber light path at one end and at least one optical fiber light path at the other end, and switches the optical fiber light path at one end to be communicated with the optical fiber light path at any one of the other ends; at least one optical fiber light path at the other end is respectively inserted into the plug 4 through the corresponding optical fibers 3.

The optical fiber 3 is a polarization-maintaining single-mode fiber or a non-polarization-maintaining single-mode fiber. The number of optical fibers 3 is selected from 1-N, where N ≧ 2, which is three for the embodiment shown in FIG. 1: a first optical fiber 3-01, a second optical fiber 3-02, and a third optical fiber 3-03.

The plug 4 is made of ceramic or glass.

The number of micropores is selected from 1-N, wherein N is more than or equal to 2.

Preferably, when the optical fiber 3 is inserted into the micro-hole of the plug 4, the micro-hole is filled with the curing adhesive, and the coating layer is removed from the part of the optical fiber 3 inserted into the micro-hole.

After the optical fiber 3 is inserted into the micro-hole, the curing glue is cured, and then the other end face of the optical fiber 3 penetrating through the plug 4 is ground and polished to be a flat end face.

Fig. 2-4 are schematic diagrams showing the first embodiment, the second embodiment and the third embodiment of the coupling structure of the SESAM and the optical fiber according to the present invention, wherein the optical fiber 3 of the first embodiment includes three fibers: a first optical fiber 3-01, a second optical fiber 3-02, and a third optical fiber 3-03; the optical fiber 3 of this second embodiment comprises one: a first optical fiber 3-01; the optical fiber 3 of this third embodiment includes five: a first optical fiber 3-01, a second optical fiber 3-02, a third optical fiber 3-03, a fourth optical fiber 3-04, and a fifth optical fiber 3-05.

Specifically, the other end face of plug 4 and the mirror end of SESAM7 are enclosed in a sealed space in the following manner:

plug 4 is placed inside glass tube 6 on one side, SESAM7 is mounted on top of the raised portion of SESAM mount 9, and SESAM7 and the raised portion are placed inside glass tube 6 on the other side.

The plug 4 and the protruding part of the SESAM mount 9 are sealed against the inner wall of the glass tube 6 by means of a sealant 5.

As shown in fig. 1, the sealant 5 includes a glass tube left end sealant and a glass tube right end sealant.

The glass tube 6 has an inner diameter slightly larger than the diameter of the spigot 4 and the protruding part of the SESAM mount 9, and the spigot 4 and the protruding part of the SESAM mount 9 are wrapped and cured by a sealant.

The SESAM7 is mounted on the SESAM mounting seat 9, and the multishaft mounting bracket 12 clamps the SESAM mounting seat 9 to adjust the relative distance and angle between the mirror-surface end of the SESAM7 and the other end surface of the plug 4, so that each working point of the SESAM7 corresponds to the position of each optical fiber 3 passing through the plug 4.

Further, TEC10 sets up on SESAM mount pad 9, controls the temperature to SESAM7, has obviously improved the heat dispersion of SESAM, has improved its life.

The TEC10 is connected with the heat sink 11, the SESAM mounting seat 9 is connected with the heat sink 11 through the TEC10, and the SESAM mounting seat 9 and the heat sink 11 are both made of materials with good heat conduction performance.

Preferably, the SESAM mount 9 is a convex structure, the outer diameter of the convex portion of which is close to the outer diameter of the plug, the SESAM7 is fixedly mounted on the convex portion of the SESAM mount 9 by an adhesive 8, and the adhesive 8 is a heat-conducting glue or a welding agent.

Further, a fiber laser 1 is provided on one side of the fiber optical path switching device 2.

The laser emitted from the fiber laser 1 is inputted to one optical fiber path at one end of the optical fiber path switching device 2.

In conjunction with this fiber laser 1, an ultrafast fiber laser produced using SESAM passive mode-locking.

Example 4

The embodiment 2 provided by the utility model does the utility model provides an embodiment of a pair of SESAM and optical fiber's coupling structure's packaging method, this packaging method is based on the embodiment of the utility model provides a SESAM and optical fiber's coupling structure, it is concrete, this packaging method includes:

step 1, injecting curing glue into the micropores of the plug 4, setting the number of the optical fibers 3 according to the requirement, wherein the number is less than or equal to the number of the micropores, stripping and wiping the coating layer at the tail part of each optical fiber 3, then respectively inserting the tail parts of the optical fibers 3 into the corresponding micropores, protruding one section of the other end face of the plug 4 after penetrating through the plug 4, curing the curing glue, and then grinding and polishing the other end face of the optical fiber 3 penetrating through the plug 4 by using a grinder to form a flat end face, wherein the end face can be coated with or not coated with a film.

Step 2, an adhesive is placed over the raised portion of the SESAM mount 9, and the SESAM7 is fixedly mounted onto the raised portion of the SESAM mount 9.

The adhesive is heat-conducting glue or welding flux, after the SESAM7 is placed on the convex part of the SESAM mounting seat 9, when the adhesive is the heat-conducting glue, the fixed mounting of the SESAM7 is realized by curing the heat-conducting glue; when the adhesive is a solder, the SESAM7 is fixedly attached by welding.

And 3, coating curing glue on the inner wall of one side of the glass tube or the outer wall of the plug, then placing the other end face of the plug 4 into the glass tube, and curing the curing glue to ensure that no glue gap exists between the plug outer wall and the inner wall of the glass tube at 360 degrees in the circumferential direction.

And 4, coating the inner wall of the other side of the glass tube or the side wall of the convex part of the SESAM mounting seat 9 with curing glue, putting the convex part of the SESAM mounting seat 9 into the glass tube, opening the optical fiber laser, adjusting parameters such as the relative distance and the angle of the SESAM7 relative to the other end face of the plug 4 through the multi-axis adjusting frame 12, optimizing the pumping current of the optical fiber laser, and realizing self-starting mode locking.

Step 5, when the number of the optical fibers 3 is at least two, adjusting the optical fiber light path switching device 2 to enable one optical fiber light path at one end to be sequentially switched to be communicated with each optical fiber light path at the other end, and sequentially testing the self-starting mode locking condition when different optical fiber links are in use; when the number of the optical fiber links for realizing the self-starting mode locking is more than 2, the SESAM mounting seat 9 is considered to be adjusted in place, the glue on the side wall of the SESAM mounting seat is solidified, and the multi-axis adjusting frame 12 is removed after the inner cavity formed by the glass tube, the plug 4 and the SESAM mounting seat 9 is in a fully closed state.

And 6, coating glue or heat conducting fins on the upper surface and the lower surface of the TEC, and mounting the whole formed by the optical fibers 3, the glass tube, the plug 4, the SESAM7 and the SESAM mounting seat 9 on a heat sink through the TEC.

Example 3

Embodiment 3 provided by the present invention is the embodiment of the structure and the packaging method of the first specific application embodiment of the coupling structure of the SESAM and the optical fiber provided by the present invention.

With reference to fig. 1 and fig. 3, the present embodiment implements a coupling method and a packaging method for a single optical fiber and an SESAM, including a ceramic plug, a polarization maintaining single mode fiber, a glass tube, a square SESAM, a heat conducting glue, a SESAM mounting seat, a TEC, and a heat sink.

With reference to fig. 1 and 3, a ceramic plug with an outer diameter of 2mm and a length of 5mm is selected, a micropore with a diameter of 128 μm is arranged at the center, and thermosetting glue is injected into the micropore.

Referring to fig. 1 and 3, a polarization maintaining single mode fiber with a cladding diameter of 125 μm is selected as the optical fiber.

Referring to fig. 3, after the coating layer of the tail portion of the optical fiber is removed, the tail portion of the optical fiber is inserted into the central micro-hole of the ceramic plug and a small section of the optical fiber is slightly exposed, and the glue is cured.

With reference to fig. 3, the plug end face and the fiber end face are polished to a flat end face.

With reference to fig. 1, an SESAM mounting seat with a 2mm diameter and a 5mm thickness of a raised portion is selected, and an SESAM with a geometric dimension of 1mm × 1mm × 1mm is mounted on the upper central area of the raised portion through a heat-conducting adhesive.

Referring to fig. 1, a quartz glass tube with an inner diameter of 2.1mm, an outer diameter of 4mm and a length of 12mm is selected, an area of approximately 3mm in width between the outer wall of the ceramic plug and the outer wall of the protruding portion of the SESAM mounting seat is coated with ultraviolet curing glue, and then the ultraviolet curing glue is respectively inserted into the front end and the rear end of the glass tube and is cured.

Referring to fig. 1, the SESAM mount and heat sink are both made of red copper and are surface plated with gold.

The present embodiment further provides a method for packaging an SESAM and an optical fiber, including the following steps:

s1, injecting heat curing glue into the plug micropore, selecting a single-mode polarization maintaining optical fiber, stripping and wiping the tail coating layer of the optical fiber, then inserting the optical fiber into the plug central micropore and protruding a section, carrying out heat curing on the glue, then grinding and polishing the plug end face protruding from the optical fiber into a flat end face by using a grinder, and plating an anti-reflection film on the optical fiber end face.

S2, applying a thermal conductive paste to the central region above the raised portion of the SESAM mount, adhering the SESAM to the region and thermally curing the same.

S3, coating ultraviolet curing glue on the outer wall of the plug, then placing the ground end face of the plug into the glass tube inwards, rotating for a plurality of times until the outer wall of the plug is in a seamless glue joint with the inner wall of the glass tube at 360 degrees in the circumferential direction, and then carrying out ultraviolet curing on the glue.

S4, coating ultraviolet curing glue on the side wall of the protruding part of the SESAM mounting seat, then putting the SESAM end of the protruding part of the SESAM mounting seat into the glass tube, opening the optical fiber laser, clamping the SESAM mounting seat by using a six-axis adjusting frame, adjusting parameters such as the distance and the angle of the SESAM relative to the grinding surface of the plug, optimizing the pumping current of the optical fiber laser until self-starting mode locking is realized, performing ultraviolet curing on the glue, ensuring that an inner cavity formed among the glass tube, the plug and the SESAM mounting seat is in a fully closed state, and then removing the six-axis adjusting frame.

S5, indium foils are placed on the upper surface and the lower surface of the TEC, and the whole formed by the optical fiber, the glass tube, the plug, the SESAM and the SESAM mounting seat is mounted on the heat sink through the TEC, so that the coupling mode and the packaging of the SESAM and the single optical fiber are completed.

Example 4

Embodiment 4 provided by the present invention is the structure and the embodiment of the packaging method of the second specific application embodiment of the coupling structure of the SESAM and the optical fiber provided by the present invention.

With reference to fig. 1 and fig. 4, the present embodiment implements a coupling manner and a packaging method of five optical fibers and an SESAM, including a ceramic plug, five polarization maintaining single mode optical fibers, a glass tube, a square SESAM, a heat conducting glue, a SESAM mounting seat, a TEC, and a heat sink.

With reference to fig. 1 and 4, a glass plug with an outer diameter of 2mm and a length of 5mm is selected, five micro-holes with a diameter of 130 μm are formed inside the glass plug, and thermosetting glue is injected into the micro-holes.

With reference to fig. 1 and 4, five polarization-maintaining single-mode fibers with cladding diameters of 125 μm were selected.

Referring to fig. 4, after the coating layers of the five optical fiber tails are removed, the five optical fiber tails are respectively inserted into five micro holes of the glass plug and a small section of the glass plug is slightly exposed, and the glue is thermally cured.

With reference to fig. 4, the plug end face and the optical fiber end face are polished to a flat end face and coated with a film.

With reference to fig. 1, an SESAM mounting seat with a 2mm diameter and a 5mm thickness of a raised portion is selected, and an SESAM with a geometric dimension of 1.5mm × 1.5mm × 1mm is mounted on the upper central region of the raised portion through a heat-conducting adhesive.

With reference to fig. 1, a quartz glass tube with an inner diameter of 2.1mm, an outer diameter of 4mm and a length of 12mm is selected, an area of approximately 3mm in width between the outer wall of the glass plug and the outer wall of the protruding portion of the SESAM mounting seat is coated with ultraviolet curing glue, and then the glass plug and the SESAM mounting seat are respectively inserted into the front end and the rear end of the glass tube, and the glue is subjected to ultraviolet curing.

With reference to fig. 1, both the SESAM mount and the heat sink are made of kovar and are surface plated with gold.

The embodiment also provides a method for packaging the SESAM and the five optical fibers, which comprises the following steps:

s1, injecting heat curing glue into the plug micropores, selecting five single-mode polarization maintaining optical fibers, stripping and wiping the tail coating layers of the five optical fibers, then inserting the optical fibers into the central micropores of the glass plug and protruding a section of the optical fibers, carrying out heat curing on the glue, then grinding and polishing the protruding plug end faces of the optical fibers into a flat end face by using a grinder, and plating an antireflection film on the end faces of the optical fibers.

S2, placing SnBi low-temperature solder on the central area above the raised part of the SESAM mounting seat, and welding the SESAM to the area.

S4, coating ultraviolet curing glue on the side wall of the protruding part of the SESAM mounting seat, then putting the SESAM end of the protruding part of the SESAM mounting seat into the glass tube, opening the optical fiber laser, clamping the SESAM mounting seat by using a six-axis adjusting frame, adjusting parameters such as the distance and the angle of the SESAM relative to the grinding surface of the plug, and optimizing the pumping current of the optical fiber laser until self-starting mode locking is realized.

And S5, adjusting the optical fiber light path switching device, sequentially testing the self-starting mode locking conditions of different optical fiber links, when the number of the optical fiber links capable of realizing the self-starting mode locking is more than 2, considering that the SESAM mounting seat is adjusted in place, curing glue on the side wall of the SESAM mounting seat, ensuring that an inner cavity formed among the glass tube, the plug and the SESAM mounting seat is in a fully closed state, and removing the six-axis adjusting frame.

S6, coating heat-conducting glue on the upper and lower surfaces of the TEC, and mounting the whole formed by the optical fiber, the glass tube, the plug, the SESAM and the SESAM mounting seat on the heat sink through the TEC, thereby completing the coupling mode and the packaging of the SESAM and the five optical fibers.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A SESAM to optical fiber coupling structure, the coupling structure comprising: -an optical fiber (3) and a SESAM (7), characterized in that said coupling structure further comprises: an optical fiber optical path switching device (2) and a plug (4);

the optical fiber light path switching device (2) comprises an optical fiber light path at one end and at least one optical fiber light path at the other end, and the optical fiber light path at one end is switched to be communicated with the optical fiber light path at any one of the other ends; at least one optical fiber light path at the other end is respectively inserted into the plug (4) through corresponding optical fibers (3);

the plug (4) comprises a respective micro-hole through which the optical fibre (3) passes from one end face to the other end face of the plug (4);

the other end face of the plug (4) and the mirror face end of the SESAM (7) are sealed in a closed space; the respective working points of the SESAM (7) correspond to the positions of the respective optical fibers (3) after passing through the plug (4).

2. A coupling structure according to claim 1, characterized by a SESAM mount (9) and a multiaxial mount (12);

the SESAM (7) is arranged on the SESAM mounting seat (9), the multi-shaft mounting rack (12) clamps the SESAM mounting seat (9) to adjust the relative distance and angle between the mirror surface end of the SESAM (7) and the other end surface of the plug (4), and each working point of the SESAM (7) corresponds to the position of each optical fiber (3) passing through the plug (4).

3. The coupling structure according to claim 1, characterized in that when the optical fiber (3) is inserted into the micro-hole of the plug (4), the micro-hole has a cured glue therein, and the portion of the optical fiber (3) inserted into the micro-hole is stripped of the coating.

4. A coupling structure according to claim 3, wherein after the optical fiber (3) is inserted into the micro-hole, the curing glue is cured and then the optical fiber (3) is polished to a flat end surface through the other end surface of the plug (4).

5. The coupling structure according to claim 1, characterized in that the plug (4) material is ceramic or glass.

6. The coupling structure according to claim 1, wherein a fiber laser (1) is provided at one side of the fiber optical path switching device (2);

and the laser emitted by the optical fiber laser (1) is input to an optical fiber light path at one end of the optical fiber light path switching device (2).

7. A coupling structure according to claim 2, wherein the SESAM mount (9) is of a male type, the SESAM (7) is fixedly mounted on top of the protruding portion of the SESAM mount (9) by means of an adhesive (8), the adhesive (8) being a thermally conductive glue or solder.

8. The coupling structure according to claim 7, characterized in that it further comprises a glass tube (6);

the plug (4) is arranged at one side inside the glass tube (6), the SESAM (7) is arranged on the upper surface of the bulge part of the SESAM mounting seat (9), and the SESAM (7) and the bulge part are arranged at the other side inside the glass tube (6);

and the convex parts of the plug (4) and the SESAM mounting seat (9) and the inner wall of the glass tube (6) are sealed by sealant.

9. A coupling structure according to claim 2, characterized in that the SESAM mount (9) is further provided with a TEC (10) for temperature control of the SESAM (7).

10. The coupling structure according to claim 9, characterized in that a heat sink (11) is connected to the TEC (10).