Patent ID: 6618416
Filing Date: 2003-09-09
Classification: B82Y,H01S

Abstract:
An InGaAlN-based semiconductor laser device, comprising a first layer of a first conductivity type, an active layer having a smaller forbidden band than that of the first layer, and a second layer of a second conductivity type having a larger forbidden band than that of the active layer, wherein the second layer includes a flat region and a stripe-shaped projecting structure; a stripe-shaped optical waveguide forming layer of the second conductivity type having a larger refractive index at the wavelength of the laser light emitting at the active layer than that of the second layer is formed on the stripe-shaped projecting structure; a current-constricting layer of the first conductivity type or of a high resistance is formed for covering a top surface of the flat region of the second layer, a side surface of the projecting structure of the second layer, and a side surface of the optical waveguide forming layer; and a difference between a thermal expansion coefficient of the current-constricting layer and a thermal expansion coefficient of the second layer is in the range of âˆ’4Ã—10âˆ’9/Â° C. to +4Ã—10âˆ’9/Â° C., wherein an InGaAlN layer included in a super-lattice structure forming the second layer or the current-constricting layer has a thickness of 50 nm or less.