Solid state laser with longitudinal cooling

Abstract

An optically-pumped laser comprises a laser cavity, a solid-state gain medium and an optically transparent heat sink (OTH) situated within the laser cavity. The gain medium and OTH are thermally coupled and at least one of the solid-state gain medium and the OTH has an etalon structure thereby improving laser efficiency. The OTH advantageously provides effective heat transfer and permits higher average power operation, particularly for thin solid-state laser materials. A metallic heat sink may be thermally coupled to the OTH to improve heat transfer. In some embodiments, the laser is end-pumped with optical pump radiation through the OTH. A second intracavity OTH may be thermally coupled to the gain medium opposite the first OTH to provide longitudinal heat transfer in both directions. A frequency-converted laser may be provided by using a nonlinear material longitudinally cooled on each end by intracavity OTHs, at least one of which comprises an etalon structure. In some frequency-converted laser embodiments, first and second converted beams are output from the laser cavity along separate optical paths in a manner that advantageously prevents intracavity interference between the two converted beams.