CN204290025U - A kind of high-power fiber pump combiner - Google Patents

Abstract

The utility model provides a technical scheme of a high-power optical fiber pump beam combiner. The method utilizes the optical fiber waveguide structure (including N input pump optical fibers, taper regions, fusion points, and output optical fibers) after tapering and shaping. The input and output ends are skillfully coated with two layers of high refractive index UV glue, so that they are fixed on an aluminum substrate with a groove, and then an aluminum upper cover with the same groove structure as the aluminum substrate is used. Glue seal to complete the pump combiner package. The pump beam combiner packaged by the utility model has a simple structure, no obvious heat accumulation phenomenon, good heat dissipation effect, and the device is not easy to be damaged, and the withstand power can reach the order of kW to several kW.

Description

A high power fiber pump beam combiner

technical field

The utility model relates to an optical device and a packaging method thereof, in particular to a high-power optical fiber pump beam combiner.

Background technique

In the prior art, it is known that the fiber pump beam combiner has the advantages of convenient use, high coupling efficiency, and high integration, and has become the main pump coupling method in fiber lasers. The main composition of the fiber pump beam combiner consists of two parts: one is the fiber waveguide structure after tapering shaping; the other is the packaging structure. The packaging of the fiber pump combiner should have the following three functions: one is to effectively fix the fiber waveguide structure in the pump combiner; the other is to effectively absorb the stray light in the pump combiner; the third is to The waste heat in the pump combiner is effectively transferred, thereby reducing the thermal effect of the pump combiner and increasing the withstand power of the pump combiner.

At present, the packaging structure of fiber pump combiners is generally complex, and the heat dissipation performance is poor, especially the package heat dissipation of kW-level high-power fiber pump combiners generally adopts water cooling, and its packaging process and structure are relatively complex. How to effectively improve the light guide and heat dissipation performance of the optical fiber pumping beam combiner, and effectively simplify the package structure so as to facilitate the use has become an important problem to be solved, which is the deficiency of the existing technology.

Utility model content

The purpose of this utility model is to provide a technical solution of a high-power optical fiber pump beam combiner for the deficiencies in the prior art. The solution is simple in structure, easy to use, good in heat dissipation performance, and can withstand power up to kW order of magnitude.

This program is achieved through the following technical measures:

A high-power optical fiber pumping beam combiner is characterized in that: it includes an upper cover, a base plate, an input pumping fiber bundle and an output pumping fiber that are welded together; the input pumping fiber bundle and the output pumping fiber are placed horizontally on On the substrate; grooves are provided at both ends and the middle of the substrate; the input pump fiber bundle is placed on the groove at one end of the substrate; the output pump fiber is placed on the groove at the other end of the substrate; the input pump fiber bundle and the output pump The welding point of the optical fiber is set on the groove in the middle of the base plate; the upper cover plate is covered on the base plate.

As an optimization of this solution: the bare fiber parts of the input pump fiber bundle are evenly dispersed, there are gaps between the bare fibers, and the bare fiber parts are fixed on the substrate by high-fold UV glue.

As a preference of this solution: the output pumping optical fiber is fixed on the substrate by high-fold UV glue coated on the optical fiber.

As a preference of this solution: the shape of the groove is semi-arc, and the inside of the groove is closely arranged with a semi-arc V-shaped groove whose taper angle is smaller than the maximum stable transmission angle of the optical fiber above the groove.

As a preference of this solution: when the bare fiber part of the input pump fiber is dispersed, all the scattered bare fiber parts are located in the same plane or dispersed in a three-dimensional space.

The beneficial effect of this scheme can be known according to the description of the above scheme, because in this scheme the length of the substrate is suitable for the length of the optical fiber waveguide structure of the pump beam combiner, the groove of the substrate is semicircular arc-shaped, and its diameter is several millimeters , the semi-arc-shaped V-shaped grooves whose cone angle is smaller than the maximum stable transmission angle of the optical fiber are closely arranged in the groove, so as to effectively absorb the stray light with a large angle that cannot be stably transmitted in the optical fiber; the bare optical fiber input to the pump optical fiber is scattered The purpose of opening is to avoid heat accumulation, because when the input optical fibers are bundled together or closely arranged, the high-fold UV glue will soak into the narrow gap between the optical fibers, thereby forming a fiber-like structure with a high refractive index inside and low outside. Such a structure cannot effectively guide the light so that the light beams are concentrated in the UV glue to form heat accumulation. Since the thermal conductivity of quartz and UV glue are both very low, this will cause serious thermal effects, thereby reducing the pump beam combiner. withstand power.

The reason for coating the bare fiber part of the input pump fiber with high-reflection UV glue is to prevent the scattered light generated near the fusion point from entering the polymer protective layer of the input pump fiber, causing unnecessary heat accumulation.

When the UV glue is directly coated on the bare fiber of the input pump fiber, the stray light has been guided out by the high-refraction UV glue before entering the polymer protective layer and absorbed by the aluminum substrate, which can effectively reduce the thermal effect.

When the output pump fiber is a polymer-clad fiber, the starting position of the UV glue coating should be flush with the polymer cladding. The purpose is to completely guide the scattered light generated near the fusion point absorbed by the polymer cladding. , and use UV glue to conduct heat conduction on the polymer cladding. If the starting position of the UV glue and the polymer cladding is not flush, the scattered light will directly enter the part of the suspended polymer cladding not covered by the UV glue, which will cause heat accumulation in the polymer cladding and reduce the pumping rate. Combiner withstand power.

It can be seen that, compared with the prior art, the utility model has a simple structure, no obvious heat accumulation phenomenon, good heat dissipation effect, the device is not easily damaged, and the withstand power can reach the order of kW to several kW. It has outstanding substantive features and Significant progress, the beneficial effect of its implementation is also obvious.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a schematic structural diagram of the upper cover sealing the pump coupler.

In the figure, 1 is the input pump fiber, 2 is the cone area, 3 is the fusion splicing point, 4 is the output pump fiber, 5 is the substrate, 6 is the V-groove, 7 is the V-groove, 8 is the V-groove, 9 The first high-refractive-index UV glue, 10 is the bare fiber input pump fiber, 11 is the second high-refractive-index UV glue, 12 is the upper cover, and 13 is the screw.

Detailed ways

All features disclosed in this specification, or steps in all methods or processes disclosed, may be combined in any manner, except for mutually exclusive features and/or steps.

Any feature disclosed in this specification (including any appended claims, abstract and drawings), unless expressly stated otherwise, may be replaced by alternative features which are equivalent or serve a similar purpose. That is, unless expressly stated otherwise, each feature is one example only of a series of equivalent or similar features.

As shown in Figure 1, the utility model includes a top cover, a base plate, an input pumping fiber bundle and an output pumping fiber that are welded together; the input pumping fiber bundle and the output pumping fiber are placed horizontally on the base plate; both ends and the middle of the base plate There is a groove; the input pump fiber bundle is placed on the groove at one end of the substrate; the output pump fiber is placed on the groove at the other end of the substrate; the fusion point of the input pump fiber bundle and the output pump fiber is set in the middle of the substrate On the groove; the upper cover plate is covered on the substrate; the bare optical fiber part of the input pump fiber bundle is evenly dispersed, and there is a gap between each exposed optical fiber, and the bare optical fiber part is fixed on the substrate by high-fold UV glue; The output pump fiber is fixed on the substrate by high-fold UV glue coated on the fiber; the shape of the groove is semi-circular arc, and the inside of the groove is tightly arranged with cone angles smaller than the maximum stable transmission angle of the fiber above the groove. Semi-circular V-groove.

The specific packaging method is:

The input pump fiber model of the 7×1 pump combiner is selected as a multimode fiber with a core of 200um/package of 220um and NA=0.22. The output pump fiber is a double-clad fiber with a silica cladding diameter of 400um. The material cladding diameter is 550um, NA=0.46.

First, the fiber waveguide structure of the pump beam combiner, which contains 7 input pump fibers 1, taper 2, fusion splice 3, and output pump fiber 4, is placed horizontally in the groove 5 on an aluminum substrate. The diameter of the groove is 3 mm. V-shaped grooves 6 with an angle of 15° are closely arranged in the left groove, and V-shaped grooves 7 with an angle of 20° are closely arranged in the groove near the welding point in the middle. V-shaped grooves 8 with an angle of 30° are closely arranged in the grooves.

Then use a clamp to fix the output pumping fiber 4 horizontally, spread the 7 input pumping fibers 1 evenly on the same plane and fix them with the corresponding clamps, and use the first high refractive index UV glue 9 Coat the bare optical fiber 10 and the polymer protective layer of the 7 input pump optical fibers until it is completely covered by UV glue, the coating length of the bare optical fiber is about 10mm, and the coating length of the polymer protective layer is not less than 5mm, and the coating is completed Finally, use a UV curing lamp to irradiate and cure the UV glue at the input end.

Then use the second high-refractive-index UV glue 11 to coat the polymer cladding of the output pump fiber 4. When coating, it should be coated from right to left. When it is close to the boundary point between the bare fiber and the polymer cladding, Slow down the coating speed to ensure that the UV glue just covers the starting point of the polymer cladding, but does not coat the bare fiber. The coating length of the output pumping fiber 4 is not less than 8mm, and the output pumping fiber should be completely covered by UV glue. After the coating is completed, use a UV curing lamp to irradiate and cure the UV glue at the output end.

Finally, as shown in Figure 2, an aluminum upper cover 12 with the same groove structure as the aluminum substrate is connected to the aluminum substrate through screws 13, and the grooves on the left and right sides of the aluminum upper cover are sealed with high-fold UV glue. Fill a certain distance (not exceeding the coating range of UV glue on the substrate), and then use a UV curing lamp to cure this part of the high-refraction glue, so as to realize the sealing of the pump combiner and complete the packaging of the pump combiner.

The test results of the pump combiner packaged by the above method are: each arm of the pump combiner is connected to a 976nm pump light source with a power of 145W, the total withstand power reaches 1015W, and it works stably for more than 1 hour. Among them, the temperature of the UV glue at the input end only rises by 24.6°C, and the temperature of the UV glue at the output end only rises by 23°C.

The utility model is not limited to the aforementioned specific embodiments. The utility model extends to any new feature or any new combination disclosed in this specification, as well as the steps of any new method or process or any new combination disclosed.

Claims (5)

1. a high-power fiber pump combiner, is characterized in that: include upper cover, substrate, the input pumping light fibre bundle be welded together and export pumping optical fiber; Described input pumping light fibre bundle and output pumping optical fiber horizontal are placed on substrate; Described substrate two ends and middle part are provided with groove; Described input pumping light fibre bundle is placed on the groove of substrate one end; Described output pumping optical fiber is placed on the groove of the substrate other end; The fusion point of described input pumping light fibre bundle and output pumping optical fiber is arranged on the groove in the middle part of substrate; Described upper cover plate covers on substrate.

2. a kind of high-power fiber pump combiner according to claim 1, it is characterized in that: the plain fiber portion of described input pumping light fibre bundle is dispersed to be opened, there is gap between each exposed optical fiber, and by height folding UV glue, plain fiber portion is fixed on substrate.

3. a kind of high-power fiber pump combiner according to claim 1, is characterized in that: described output pumping optical fiber is rolled over UV glue by the height be coated on optical fiber and is fixed on substrate.

4. a kind of high-power fiber pump combiner according to claim 1, is characterized in that: the shape of described groove is semicircular arc, and inside grooves is closely placed with the semicircular arc V-type groove that angle of taper is less than the maximum stable transmission angle of optical fiber above groove.

5. a kind of high-power fiber pump combiner according to claim 1, is characterized in that: the plain fiber portion of described input pumping light fibre is all arranged in same plane or is scattered in three dimensions.