Study of Nd: YAG solar laser output performance in end pumping and side pumping configurations

Abstract

Since the report of the first sun-pumped solid-state laser, several pumping schemes have been proposed for enhancing the solar-laser performance. Although the most efficient laser systems have end-pumping approaches, side-pumping configurations are very suitable for reducing the thermal loading problems and consequently producing higher laser beam quality. Here we report a study of the Nd: YAG solar-lasers performance by using either end-pumping or side-pumping techniques. The end-pumping configuration provides simultaneously, in multimode regime, the maximum laser power (120 W continuous wave), the highest collection efficiency (32.1 W/m²), the highest slope efficiency (8.9 %), the lowest threshold pump power (192 W) and in monomode operation the highest fundamental-mode collection efficiency (7.9 W/m²) the highest solar laser brightness (6.5 W). However, the side-pumping approach is very preferred for achieving high laser beam quality in monomode operation (M² < 1.05).