| 摘要 |
PURPOSE:To obtain a semiconductor laser which can be operated with stable, low noise for a returning light with good reproducibility by using a pair of curved mirrors as the resonator of a laser. CONSTITUTION:Reflectivity is varied at the end faces of laser resonator faces 123a, 123b by forming the shape of the faces 123a, 123b in curved faces, and a space distribution of the threshold gain of a semiconductor laser is controlled. Thus, an axial mode selection ratio can be weakened, and a multi-axis mode oscillation can be maintained at the time of implanting carriers highly. Accordingly, the space coherence of the laser light is not enhanced while a fundamental lateral mode is held. Thus, even if a returning light from a disk medium is large, of the order of several %, the noise level is not raised. |
