Highly efficient side-pumped solar laser

The power density of solar on the earth is so low that it can´t achieve to pump laser. To surpass the lasing threshold, the solar has to be highly concentrated. We propose the highly efficient concentration system, which is composed by a Fresnel lens and a three-dimensional compound parabolic concentrator (3-DCPC). With the help of 3-DCPC, we increase the concentration ratio which is applied to the laser crystal. The exit of the 3-DCPC is placed in one focus of an elliptical chamber, so the solar is coupled into the elliptical chamber, pumping Nd:YAG laser media. Laser output of 6.2 W has been achieved, and the collect efficiency is 6.2W/m² in the experiment.