FIBER LASER, SPONTANEOUS EMISSION LIGHT SOURCE AND OPTICAL FIBER AMPLIFIER

摘要

In a fiber laser, a spontaneous emission light source and an optical fiber amplifier, it has been common practice to excite a fiber doped with thulium (Tm) ions with 0.67 mum or 0.8 mum excitation light. This poses a problem such that performance deterioration is intensified with the passage of time. In the invention, 1.2 mum light is used as an excitation light, or use is made of an excitation light source capable of exciting thulium from ground level <3>H6 to excitation level <3>H5. In a preferred mode, a host glass to be doped with Tm has been specified, thereby enhancing 2.3 mum-band luminous efficiency.