Patent attributes
A semiconductor laser device has a red laser element and an infrared laser element on a substrate. The red laser element has a double hetero structure in which an InGaP-based or AlGaInP-based active layer is interposed between a first conductivity type cladding layer and a second conductivity type cladding layer having a ridge. The infrared laser element has a double hetero structure in which a GaAs-based or AlGaAs-based active layer is interposed between a first conductivity type cladding layer and a second conductivity type cladding layer having a ridge. Provided that a first electrode formed over the second conductivity type cladding layer has a width W1 in a direction perpendicular to a cavity length direction and a second electrode formed over the second conductivity type cladding layer has a width W2 in a direction perpendicular to a cavity length direction, the relations of W1>W2 and 80 μm≧W2≧60 μm are satisfied.