OPTICAL-PROPERTIES AND LASER PERFORMANCE OF NEODYMIUM-DOPED SCHEELITES CAWO4 AND NAGD(WO4)(2)

Nd-doped CaWO4 (CWO) and NaGd(WO4)(2) (NGWO) single crystals with good optical quality have been grown by the Czochralski technique. The neo dymium distribution coefficient in these matrices is about 0.4 for CWO and close to unity for NGWO. Polarized absorption and emission spectr a have been recorded at room temperature and used to calculate the abs orption and stimulated emission cross-sections. 1 and 2% Nd:CWO and 1% Nd:NGWO laser rods have been tested in a cavity longitudinaly pumped by an 1 W AIGaAs laser diode and compared to Nd:YAG and Nd:YVO4 rods i n the same conditions. The 2% Nd:CWO rod exhibits the best performance with slope efficiencies of 64%, higher than in the case of YAG and eq ual to the YVO4 samples. The dependence of the laser output power vers us the diode temperature has been measured for all these materials. Th e laser output of Nd:CWO was found to be nearly as stable as for Nd:YV O4 and much more stable than in the case of Nd:YAG. A CWO microchip ha s also been tested for the first time to our knowledge.