DOUBLE CLAD FIBER, COUPLING STRUCTURE, FIBER AMPLIFIER, AND FIBER LASER

摘要

PROBLEM TO BE SOLVED: To provide a fiber capable of efficiently introducing signal light and exciting light to a pumping medium, and to provide a coupling structure, a fiber amplifier and a fiber laser using the fiber.;SOLUTION: A double clad fiber has a core and an inner clad surrounding the outer circumference of the core, guiding signal light and exciting light. The double clad fiber is characterized in that the two ends A, B of the double clad fiber are in a relation in which a mode field diameter for the signal light is AB and in which the inner clad diameter is AB. The coupling structure is characterized in that, to one end of this double clad fiber, there are connected a signal light guiding fiber and an exciting light guiding fiber and that, to the other end, the pumping medium is connected to introduce the signal light and the exciting light to the pumping medium. The coupling structure is also characterized in that the signal light guiding fiber and the exciting light guiding fiber are connected to the smaller end of the mode field diameter of the double clad fiber.;COPYRIGHT: (C)2007,JPO&INPIT