SEMICONDUCTOR LASER DEVICE AND OPTICAL PICKUP DEVICE

摘要

A semiconductor laser device has a semiconductor laser and a polarizing diffraction grating that is arranged ahead of the semiconductor laser. A reflected light from an optical recording medium is diffracted by the polarizing diffraction grating according to the polarization direction of the reflected light. The reflected light is thereby deviated from the direction toward the semiconductor laser to prevent the reflected light from returning to the semiconductor laser.