Long-distance weak-coupling optical fiber coupler and application thereof

Abstract

A long-distance weak-coupling optical fiber coupler comprises two optical fibers (201 and 202), a coupling area (501) and four terminals (101, 102, 103 and 104). The two optical fibers (201 and 202) are arranged in parallel at the equal interval and share a common outer cover layer (301). The two optical fibers can generate weak coupling in the outer cover layer (301) to form the coupling area. The four terminals (101, 102, 103 and 104) are arranged outside the outer cover layer (301). The long-distance weak-coupling optical fiber coupler is characterized in that the length of the coupling area (501) is between 2 meters and 20 meters, and the horizontal distance between the centers of the two optical fibers is between 100 micrometers and 500 micrometers. The long-distance weak-coupling optical fiber coupler eliminates a traditional method using an optical fiber combiner to generate pumping laser to couple an inner cover layer of an active double-cover-layer optical fiber and remarkably improves performance.

Description

technical field [0001] The invention relates to an optical fiber coupler, in particular to a long-distance weakly coupled optical fiber coupler. Background technique [0002] We know that fiber lasers have developed rapidly in recent years. Its types include fiber-optic pulsed lasers, fiber-optic high-power CW lasers, and fiber-optic high-power quasi-CW lasers. These fiber lasers all need to couple the pump laser light into the inner cladding of the active fiber for optical amplification. [0003] The current method of coupling the pump laser light into the inner cladding of the active fiber is to use a fiber combiner, which is divided into two types: N x 1 and N +1 x 1. The former couples N beams of pump light into the inner cladding of the active fiber; the latter couples N beams of pump light into the inner cladding of the active fiber while keeping the signal light transmission of the central core unchanged. In actual use, the effect is obviously deviated from the ide...

AI Technical Summary

Problems solved by technology

Scattering, reflections, and mode crosstalk can occur at this point

2 After the pump light enters the inner cladding of the active fiber, it crosstalks with the signal light. After passing through the reflection point, the reflected light of the signal light enters the optical path of the pump light, and thus enters the inside of the pump semiconductor laser. Will cause the pump laser to work unstable, damaged, or burned

This is extremely detrimental to the work of fiber lasers and fiber amplifiers

3 The optical power density of the optical fiber combiner at the beam combining point and the bifurcation connection is high, and the heat accumulates. Long-term work is easy to cause heat, which causes the waveguide waveguide to change, thereby reducing or even destroying the optical fiber combiner. work performance

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