Patent ID: 7738521

Claim:
A semiconductor laser device comprising: at least cladding layers comprised of semiconductor crystals of n and p conduction types and an active layer disposed between the cladding layers and comprised of semiconductor crystals with a forbidden band width narrower than a forbidden band width of the cladding layers, the cladding layers and the active layer being formed above a single crystal substrate of n conduction type; a current blocking layer provided with a groove-like current conduction region on the cladding layer of the p conduction type and comprised of a n conduction type or semi-insulating semiconductor layer, the cladding layer of the p conduction type being positioned on a side of the active layer opposite to the single crystal substrate, with the active layer being used as a reference position so that said active layer is formed between the current blocking layer and the substrate; and a structure for burying the current blocking layer with a re-growth cladding layer comprised of the p conduction type semiconductor so that current blocking layer is formed between a portion of the re-growth cladding layer and the active layer; a first electrode being positioned on the single crystal substrate opposite to a side of the cladding layer of the n conduction type; and a second electrode being positioned on the side of the re-growth cladding layer comprised of the p conduction type semiconductor; wherein a portion of the re-growth cladding layer is a super lattice cladding layer in which a semiconductor layer with a wide forbidden band width and a semiconductor layer with a narrow forbidden band width are alternately laminated at a period of 4 nm or more and 10 nm or less.