Polarization maintaining fiber side-pumped coupler and manufacturing method thereof

Abstract

The invention discloses a polarization maintaining fiber side-pumped coupler and a manufacturing method thereof. According to the coupler, a fiber core and a stress structure of a polarization maintaining main fiber connection part are kept complete; the polarization maintaining main fiber connection part is provided with an exposed inner cladding radial outer surface; and an end face structure of a pumped fiber connection end is in complementary fit with and tightly attached to the inner cladding radial outer surface. The manufacturing method comprises the following steps of: removing coatings of the polarization maintaining main fiber connection part and the pumped fiber connection end; preprocessing the pumped fiber connection end to form the end face structure of which the shape is complementary to that of the inner cladding radial outer surface at the polarization maintaining main fiber connection part; and correspondingly matching the end face structure of the pumped fiber connection end with the inner cladding radial outer surface of the polarization maintaining main fiber connection part, and eliminating air between the end face structure and the inner cladding radial outer surface, so that the pumped fiber connection end and the polarization maintaining main fiber connection part are integrated. The fiber core and the stress structure of the connection part are kept complete in the manufacturing process. The stress structure and the fiber core of the polarization maintaining main fiber connection part are not damaged, and the coupler is high in polarization extinction ratio and signal transmittance.

Description

technical field [0001] The invention relates to the technical field of lasers, in particular to a polarization-maintaining fiber side-pumped coupler and a manufacturing method thereof. Background technique [0002] Single polarization output fiber lasers and amplifiers have broad application prospects in industrial processing, military and medical fields. However, the single polarization output fiber laser power output level is directly limited by the power of the pump light coupled into the polarization maintaining gain fiber. In order to increase the power of the pump coupler, a pump source with high-brightness free-space output is commonly used now, and is coupled into the polarization-maintaining gain fiber from the end face by a coupling lens. But this kind of system built with discrete components has poor stability. In addition, a fused tapered end-face pump coupler can also be used to couple the pump source output from the pigtail into the polarization-maintaining g...

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Problems solved by technology

However, both methods can only couple the pump light from the end face, and the number of coupling interfaces is limited

[0003] In order to further increase the number of coupling points and increase the coupling power, side coupling methods have also been proposed in the prior art, mainly V-groove side pumping, microprism side coupling, etc., but these coupling methods are only applied to non-polarization-maintaining fibers; Moreover, its coupling efficiency is lower than 90%, and the stability of the coupler is poor, which cannot meet the needs of industrial applications

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