Patent ID: 7965752

Claim:
A semiconductor laser device operable to emit light having a desired wavelength in the green spectral range, the semiconductor laser device comprising a pumping source and a laser structure further comprising a substrate, a first cladding layer comprising one or more GaN layers, AlGaN layers, AlInGaN layers, or combinations thereof, and one or more active region layers comprising a plurality of InGaN quantum well layers and a plurality of quantum well barrier layers comprising GaN, InGaN or combinations thereof positioned between the InGaN quantum well layers, and at least two waveguide layers comprising one or more GaN layers or one or more InGaN layers, the InGaN layers having a lower concentration of In than the quantum well layers, with the one or more active layers positioned between the waveguide layers, wherein: the first cladding layer is positioned on the substrate, and the one or more active region layers are positioned above the first cladding layer; the one or more active region layers comprise a number of quantum wells having a spontaneous emission peak wavelength that is greater than about 520 nm at a reference pumping power density; the laser structure further comprises a net optical loss coefficient of light propagating in a waveguide mode within the laser structure; the pumping source is configured to pump each quantum well at a pumping power density such that a stimulated emission peak of each quantum well is within the green spectral range; and the number of quantum wells within the one or more active region layers are such that a net optical gain of the quantum wells is greater than the net optical loss coefficient of the semiconductor laser device at the desired wavelength in the green spectral range.