To stabilize the oscillation characteristic of a laser by adopting the structure which does not change the reflection characteristics of fiber gratings with a ferrule used for the distribution reflector of a laser module from those at the time of manufacture of the gratings.
Only the non-grating forming parts 14 and 15 of the fiber gratings 10 are soldered 20 to the ferrule 18 and the grating forming part 13 is not subjected to metal vapor deposition, by which the structure to lessen or prevent the deterioration of the gratings 11 by the heat of the solder and to prevent the exertion of a stress on the grating forming part is obtained. A metallic coating layer is formed on at least one non-grating forming part of the non-grating forming parts 14 and 15 and the non-grating forming parts are soldered and fixed via the metallic coating layer to a supporting member, by which the deterioration of the gratings by the heat of the solder is lessened or prevented.
KATO YUJI
MUGINO AKIRA
OMURA HIDEYUKI
