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, 𝜃=57° cut 9 mm thick AgGaSe2 crystal for the first time by sum-frequency-mixing of the fundamental with its second harmonic, the latter being obtained using another type-I, 𝜃=55° cut 11 mm thick AgGaSe2 crystal. The energy conversion efficiencies 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 𝜇m, 𝑃(20) line. A compact TEA CO2 laser source has been built in the laboratory.

[学科分类] 物理（综合）

[关键词] Nonlinear optical material;third harmonic generation;AgGaSe2 crystal.