Semiconductor laser unit and optical pick-up device using the same

摘要

An aperture for shielding scattered light having an intensity of less than 1/e2 of a peak value included in laser light emitted from a semiconductor laser is provided at a cap which houses a semiconductor laser and a photoreceptor. A semiconductor laser unit having less stray light incident and detected by the photoreceptor is provided by restraining light subjected to the Fresnel reflection in a hologram device located close to a light source.