No abstract

We report a room-temperature diode pumped single frequency Tm:YAP laser. Two uncoated fused silica etalons were used as mode selectors. The maximum single frequency output power was 344 mW at wavelength of 1988 nm. The slope efficiency of single-frequency laser operation was 33% and the optical-to-optical conversion efficiency was 14%. The beam propagation factors M 2 were measured as 1.44 and 1.43 in x and y directions, respectively.

No abstract

We test the performances of a Nd:YAG rod with a grooved sidewall in two solar pumped laser setups. In both cases, a Fresnel lens with a surface of 1.03  m2 is used as the primary solar light concentrator. In the first setup, a ceramic conical cavity is used as the secondary concentrator. Maximum output power of 20.3 W is obtained, corresponding to a slope efficiency of laser output power with respect to focused solar power of 8.34%. In the second setup, a water tube lens is added in a copper conical cavity to further increase the solar energy concentration; from this setup, 27 W output power is obtained, the slope efficiency of laser output power with respect to focused solar power is 9%. In both cases, the performances of the grooved rod are compared with those of an unpolished rod. The efficiency and the beam quality with the grooved rod are superior to those of the unpolished rod.