GAIN CLAMPED AMPLIFIER USING DOUBLE CLAD FIBER

摘要

A gain-clamped optical amplifier using a double clad structure is provided to cause laser oscillation, due to amplification of spontaneously-emitted light, in a first clad. An optical fiber includes a core(201), a first clad(202), and a second clad(203). The core is doped with a gain medium in order to amplify an optical signal. The first clad comes in contact with the outside of the core and has a refractive index lower than that of the core. The second clad comes in contact with the outside of the core and has a refractive index lower than that of the first clad. A light emitting element provided a pumping light source for inverting the density of the gain medium. A resonant unit causes laser oscillation by performing an amplification operation in the first clad by causing resonance with spontaneous light emitted from the gain medium density-inverted by the pumping light source.