Patent ID: 8170073

Claim:
Laser apparatus comprising,: a laser-resonator formed by a plurality of resonator mirrors; an epitaxially grown semiconductor multilayer gain-structure, the gain-structure having first and second surfaces and including a plurality of active layers spaced apart by barrier layers and being located in the laser-resonator, wherein all of the resonator mirrors are spaced from the gain structure; a diamond heat-spreader having first and second opposite surfaces, the first surface of the diamond heat-spreader being bonded to the second surface of the gain-structure; an arrangement for delivering optical pump-radiation having a pump-radiation wavelength to the gain-structure such that a portion of the pump-radiation energizes the gain-structure and generates fundamental-wavelength laser-radiation which circulates in the laser-resonator, with a residual portion of the pump-radiation being converted to heat in the gain-structure; a heat-sink member in thermal contact only with the second surface of the diamond heat-spreader, the heat-sink member including an aperture and being configured such that heat is removed from the gain-structure only via the second surface of the gain-structure and the diamond heat-spreader, while allowing access, via said aperture, to the energized gain-structure by the laser radiation circulating in the laser-resonator; and wherein there is no arrangement for extracting heat from the gain-structure via the first surface thereof and wherein the gain structure, heat spreader and heat-sink member define a transmissive path to allow the fundamental radiation to circulate in the resonator.