Semiconductor laser and light-sensing device using the same.

摘要

A semiconductor laser comprises AlGaAs-type semiconductor layers (SL) deposited on a substrate (101) and a current constriction layer (109) having at least one stripe-shaped current injection region (112). The semiconductor layers comprise: a first cladding layer (103) of the first conductivity type, a first optical waveguide layer (104) of the first conductivity type formed on the first cladding layer, an active layer (105) formed on the first optical waveguide layer and having a quantum-well structure, a second optical waveguide layer (106) of a second conductivity type formed on the active layer, a second cladding layer (107) of the second conductivity type formed on the second optical waveguide layer, and a contact layer (108) formed on the second cladding layer. The active layer has flatness of such a degree that roughness with respect to a reference surface within a unit area of 1 mm x 1 mm is no more than +/-0.1 mu m, the width of the current injection region of the current constriction layer is between 100 mu m to 250 mu m, and the resonator length is between 500 mu m to 1,000 mu m. This semiconductor laser is part of a light-sensing device which contains a light receiving optical system and further a light-transmitting optical system comprising a diffraction grating and a lens with toric or anamorphic aspheric surface.