Cladding mode light removal structure and laser device

Abstract

The present invention provides a cladding mode light removal structure capable of effectively removing cladding mode light while suppressing heat generation in the coating of an optical fiber. A cladding mode light removal structure 1 is provided with: an exposed cladding part 28 where a cladding 24 of an input-side optical fiber 20 is exposed; an exposed cladding part 38 where a cladding 34 of anoutput-side optical fiber 30 is exposed; a fusion splicing part 40 where the exposed cladding parts 28, 38 are fusion spliced; a high refractive index resin 50 having a refractive index higher than or equal to the refractive index of the cladding 24; and a low refractive index part S comprising a medium having a refractive index lower than the refractive index of the cladding 34. The high refractive index resin 50 is provided within a housing space R of a fiber housing part 10 so as to cover a downstream side end of a coating 26, the whole of the cladding 24 exposed in the exposed cladding part 28, the fusion splicing part 40, and part of the cladding 34. The low refractive index part S is located between the high refractive index resin 50 and a coating 36 of the output-side optical fiber30 and around the output-side exposed cladding part 38.

Description

technical field [0001] The present invention relates to a structure for removing cladding mode light, and more particularly to a structure for removing cladding mode light propagating through the cladding of an optical fiber in a laser device such as a fiber laser. Background technique [0002] In laser devices such as fiber lasers, some of the light propagating in the core of the optical fiber may leak to the cladding due to the deviation of the optical axis at the fusion joint between the optical fibers or the slight bending of the optical fiber. Light propagates inside as cladding mode. Such cladding mode light causes deterioration of the quality of the laser light output from the laser device, and therefore it is preferable to remove the cladding mode light before outputting the laser light from the laser device. With the increase in output of laser devices such as fiber lasers, the power of such cladding mode light has also increased, and the desire for removal of the ...

AI Technical Summary

Problems solved by technology

In addition, it can also be considered that even if the cladding mode light L R The coating 520A is not directly incident, because the resin 540 absorbs the cladding mode light L R The heat generated will also be transferred to the coating 520A through the resin 540, resulting in a high temperature of the coating 520A.

In this way, if the coating 520A becomes high temperature, there is a possibility that the coating 520A may catch fire and the optical characteristics of the optical fiber 510 may deteriorate.

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