Semiconductor laser device.

摘要

A semiconductor laser device comprises a semiconductor laser light emitting element (1), and a cap (5) that covers and hermetically seals the laser light emitting element. Laser light emitted from the element goes out through a hole formed in the top wall of the cap (5). Reflected light blocking means is disposed in the hole in the top wall of the cap. The reflected light blocking means comprises a twisted-nematic liquid crystal cell and a pair of polarizers (61,62) between which the twisted-nematic liquid crystal cell (7) is disposed.