| 摘要 |
PROBLEM TO BE SOLVED: To surely lead to a double-clad fiber pumping light from a plurality of semiconductor lasers. SOLUTION: The double-clad fiber 12 is provided with a core 1202 wherein laser active elements are dissolved, a first clad 1204 that is located in the outer periphery of the core 1202 and has a regular-pentagon cross section, and a second clad 1206 that is located in the outer periphery of the first clad 1204. A first clad exposing part 1210 wherein the second clad 1206 is removed to expose the first clad 1204 is provided in the lengthwise direction of the double-clad fiber 12. In this case, three optical fibers 18 for leading pumping light are used. The ends (light outgoing ends) of the respective optical fibers 18 for pumping light in its lengthwise direction are formed as a flat and thin/narrow end face 18A, and the entire areas of the end face 18A are joined with three side faces 1204A of the first clad 1204 in the first clad exposing part 1210. COPYRIGHT: (C)2009,JPO&INPIT |
