Solar-pumped lasers

Various gas and solid solar-pumped laser schemes are considered, including: photodissociative gas lasers with lower laser level depopulation caused by a chemical reaction, radiative decay, and collisional processes; close-cycle GDL with solar-heated lasing gas; CO2-lasers with IR pumping by the solar-heated black body; solid lasers with different active media, such as YAG:Nd, Nd-glass, and solid lightguide schemes. Maximum-efficiency regions are determined for different active media parameters such as density, absorption cross-section of solar radiation, collisional quenching rate of laser levels, and required dimensions of solar concentrators and active media. The two presently available schemes with an acceptable efficiency (3-6 percent) are the close-cycle GDL and the solid lightguide solar-pumped laser.