SEMICONDUCTOR LIGHT-EMITTING DEVICE

PURPOSE:To improve noise characteristics, and to obtain excellent focused beams, an optical system therefor is simple, by disposing a semiconductor laser- pellet having small astigmatic difference so that an optical reflecting film having low optical reflectance is opposed to the optical reflection plane of a stem. CONSTITUTION:The semiconductor laser-pellet 5 is bonded with a stud 2 through a heat-sink 4 consisting of silicon or diamond. Beams emitted to the stem 1 side from the semiconductor laser-pellet 5 are reflected at a considerably high rate because the surface of the stem 1 is plated with gold, and return to the semiconductor laser-pellet 5. Reflected light is injected again because there is the optical reflecting film 5B at low optical reflectance on the pellet. An oscillating spectrum, which has been one originally, can be changed normally into a large number of the spectra by injecting reflected light again by approximately 5%. Beams emitted to the DAD side from the semiconductor laser-pellet 5 are also reflected and return, but the quantity of reflected light being reinjected is extremely little becaue an optical reflecting film 5A having high optical reflectance exists on the pellet, and beams emitted to the DAD side exert little influence.