Efficient continuous-wave frequency doubling of a tunable CO2 laser in AgGaSe2

摘要

Second-harmonic output at 4.6-5.5 mu m of the order of 6 mW with a 0.12% external conversion efficiency has been obtained by pumping a AgGaSe2 crystal with a low-power cw CO2 laser. The surface damage threshold of AgGaSe2 for cw radiation was found to be inside the limit of 33-45 kW/cm(2) in the 9.2-10.8-mu m wavelength region. Another important limitation of the pump power connected with a thermal lensing effect in crystal was determined experimentally. A comparison was made of AgGaSe2 and ZnGeP2 crystals as materials suitable for the efficient generation of the second harmonic of cw CO2 laser radiation. (C) 1997 Optical Society of America.