SEMICONDUCTOR LASER AND LASER MODULE

摘要

PROBLEM TO BE SOLVED: To provide a DFB semiconductor laser whose power can be increased and which can stably oscillate in a single mode. SOLUTION: The semiconductor laser has a waveguide structure by which oscillation in lateral mode and in multimode can be performed and has an absorption layer for increasing the loss in modes other than the (n) order mode (n>=1) or a refraction grating for selectively reducing the gain which is formed in a specified position of a resonator. In this way, a DFB semiconductor laser which oscillates in a single mode in an (n) order mode can be obtained.