LASER APPARATUS HAVING PROTECTION MEMBER INSTALLED AT LIGHT-EMISSION END OF MULTI-MODE OPTICAL FIBER

摘要

PURPOSE: A laser apparatus having a protection member installed at a light-emission end of a multi-mode optical fiber is provided to protect a light emission end of a multi-mode optical fiber from particles and contaminants by installing a protection member having a light emission window. CONSTITUTION: A laser apparatus includes a plurality of semiconductor laser elements, a multi-mode optical fiber, and an optical condensing system. The semiconductor laser elements(LD1-LD8) are used for emitting laser beams. The multi-mode optical fiber(13) has a light entrance end and a light emission end. The optical condensing system(12) collects the laser beams emitted from the semiconductor laser elements, and couples the collected laser beams to the light entrance end of the multi-mode optical fiber. The laser apparatus further includes a protection member which is arranged at the light emission end of the multi-mode optical fiber in order to protect the light emission end from atmosphere. The protection member has a light emission window located at a predetermined distance from the light emission end.