Patent ID: 8000371

Claim:
A semiconductor gain structure to be used in an optically pumped laser system, said system including a laser pump for emitting a pump beam at a pump wavelength, comprising: a heat sink; a distributed non-epitaxial Bragg reflector structure disposed over said heat sink, said distributed non-epitaxial Bragg reflector having a reflectivity of at least 99.9% to light at a wavelength between 440 nm and 550 nm and a reflectivity lower than 5% to light in the wavelength range of 370 nm-425 nm; and a gain structure disposed over said distributed Bragg reflector structure, comprising at least gallium nitride and having formed therein a plurality of quantum well structures which are the primary pump light absorbing elements in the gain structure, each said quantum well structure comprising a quantum well layer of substantially In x Ga 1-x N with 0.10×0.5 disposed between upper and lower layers of substantially In y Ga 1-y N with 0.0<y≦0.4 said gain structure having a thickness which is the sum of the product of the thickness of each layer comprising said gain structure multiplied by that layer's refractive index and also an integer multiple of the pump wavelength and lasing wavelength; said quantum well layers arranged in groups selected from single, double, and triple quantum well groups, to thereby form at least a portion of a gain structure sub-cavity, said gain structure sub-cavity having a primary optical axis; each said quantum well group located at and generally centered on an anti-node of a standing wave pattern of a beam at the lasing wavelength of the semiconductor gain structure determined by the local overlap between the anti-nodes of standing wave patterns at the pump wavelength and lasing wavelength along an axis of and within said semiconductor gain structure.