Patent attributes
A semiconductor laser device has on a compound semiconductor substrate at least a lower cladding layer, an active layer, an upper cladding layer and a contact layer. An upper part of the upper cladding layer and the contact layer are formed as a mesa-structured portion having a ridge stripe pattern, and the both sides of the mesa structured portion are buried with a current blocking layer. The laser device includes the current blocking layer having a pit-like recess penetrating thereof and extending towards the compound semiconductor substrate, and a portion of the recess other than that penetrating the current blocking layer being covered or buried with an insulating film or a compound semiconductor layer with a high resistivity. The compound semiconductor substrate and the electrode layer thus can be kept insulated in an area other than a current injection area, thereby non-emissive failure due to short-circuit is prevented.