Abstract: A thermally actuated adaptive optic includes a base, a reflector, and a plurality of actuators coupled therebetween. The reflector has a light-receiving front surface, and a back surface facing the base. Each actuator includes a bracket rigidly bonded to the reflector at a perimeter of the reflector, and an inner rod and an outer rod. Each rod is rigidly connected between the bracket and the base, with the inner rod being closer to a center of the reflector. The length of each rod is temperature dependent. In another adaptive optic, the rods are instead bonded directly to the reflector. This adaptive optic may be modified to implement an integrally formed, thermally actuated support. The disclosed adaptive optics are suitable for use in laser systems, allow for significant cost savings over piezoelectric devices, provide a reflective area free of surface-figure perturbations caused by the actuator-interfaces, and are relatively simple to manufacture.

Abstract: A traveling wave ring-resonator is configured to deliver CW single-longitudinal-mode radiation having a fundamental wavelength characteristic of an optically pumped gain-element in the resonator. The delivered fundamental-wavelength radiation is the output-radiation of the resonator. An optically nonlinear crystal is located in the resonator and arranged to convert a fraction of fundamental-wavelength radiation into second harmonic radiation. The conversion of this fraction of fundamental-wavelength radiation to second-harmonic radiation minimizes mode-hopping in the output radiation.

Abstract: A method for optically pumping a gain-medium with partially polarized or unpolarized pump-light having a wavelength at which that gain-medium has an absorption that is dependent on the polarization plane of the pump-light is disclosed. The pump-light is directed into the gain-medium. The strongest-absorbed polarization component of the pump-light is substantially absorbed and the weakest-absorbed polarization component is partially transmitted by the gain-medium. The polarization plane of the transmitted component is rotated through 90 degrees and the polarization-rotated pump-light is directed back into the gain-medium, wherein it is substantially absorbed.

Abstract: A method for optically pumping a gain-medium with partially polarized or unpolarized pump-light having a wavelength at which that gain-medium has an absorption that is dependent on the polarization plane of the pump-light is disclosed. The pump-light is directed into the gain-medium. The strongest-absorbed polarization component of the pump-light is substantially absorbed and the weakest-absorbed polarization component is partially transmitted by the gain-medium. The polarization plane of the transmitted component is rotated through 90 degrees and the polarization-rotated pump-light is directed back into the gain-medium, wherein it is substantially absorbed.