BEAM COUPLING DEVICE AND OUTPUT RECOVERY METHOD FOR BEAM COUPLING DEVICE

摘要

Provided are a beam coupling device and the like. The beam coupling device causes beams from a plurality of light sources and one or more spare light sources to be incident on a beam coupling optical system and to be coupled and outputted after the passage thereof through a beam coupling element, detects a breakdown in the plurality of light sources, moves at least some of the respective light sources and spare light sources and the beam coupling optical system, and causes a beam to be incident on the beam coupling optical system from the spare light source in place of the beam from the light source that has broken down and to be coupled with the beams from the plurality of light sources in an optical path after the beam coupling element.