Efficient second harmonic generation of a high-power picosecond CO2 laser

A comparative analysis of AgGaSe2, GaSe, CdGeAs2, and Te for second harmonic generation (SHG) of a picosecond CO2 laser at intensities up to 50 GW/cm(2) is presented. We demonstrate external energy conversion efficiency of >20% in AgGaSe2. Conversion efficiency >5% is measured in GaSe and CdGeAs2. Self-focusing and multifilamentation are found to severely limit the SHG process in CdGeAs2 and Te at such high fields. Demonstration of >= 150 MW SH pulses for a 10 mu m picosecond pump, in combination with femtosecond CO2 laser development, will open new strong- field applications in the 4.5-5.5 mu m range. (C) 2022 Optica Publishing Group

Automated summary

This study presents a comparative analysis of AgGaSe2, GaSe, CdGeAs2, and Te for second harmonic generation (SHG) at high intensities. The results demonstrate an external energy conversion efficiency of >20% in AgGaSe2, and >5% in GaSe and CdGeAs2. However, self-focusing and multifilamentation severely limit the SHG process in CdGeAs2 and Te at such high fields.