Patent ID: 9690050
Date: 2017-06-27
CPC Classifications: G02B,H01S

Claim:
1. A laser unit comprising: a plurality of multi-mode semiconductor lasers configured to output laser lights in multi-mode; an optical multiplexer configured to multiplex and output the laser lights; a multi-mode optical fiber configured to connect the multi-mode semiconductor lasers to the optical multiplexer, and including a core portion, a cladding portion formed at an outer periphery of the core portion, and a coated portion coating an outer periphery of the cladding portion; a first bending portion formed to the multi-mode optical fiber and bent with a predetermined bending length and at a predetermined first bending radius; a radiation portion formed outside the coated portion at the first bending portion, and configured to radiate heat of the multi-mode optical fiber; and a second bending portion formed to the multi-mode optical fiber between the first bending portion and the optical multiplexer and bent at a predetermined second bending radius, wherein increase in a temperature at the second bending portion is restrained by radiation from the radiation portion.