Third harmonic generation of CO2 laser radiation in AgGaSe2 crystal

摘要

Generation of third harmonic of CO2 laser radiation has been obtained in a type-II, e???=57?° cut 9 mm thick AgGaSe2 crystal for the ???rst time by sum-frequency-mixing of the fundamental with its second harmonic, the latter being obtained using another type-I, e???=55?° cut 11 mm thick AgGaSe2 crystal. The energy conversion ef???ciencies obtained for second harmonic and third harmonic generations are 6.3% and 2.4% respectively with the input fundamental pump power density of 5.9 MW/cm2 only. The wavelength of the fundamental CO2 laser radiation used for the generation of harmonics is 10.6 e???m, e?‘?(20) line. A compact TEA CO2 laser source has been built in the laboratory.