Highly efficient side-pumped solar laser

Abstract

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 concentrateion 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/m 2 in the experiment.

Solar-Pumped TEM_00 Mode Nd:YAG laser

“…The rear mirror is high reflection coated (HR, 99.8% @ 1064 nm), while the output mirror is partial reflection coated (PR, 94%). A -0.8 m RoC (Radius of Curvature) output mirror with 94% reflectivity and a -2 m RoC rear mirror combination offers the maximum laser output power of 8.1 W, corresponding to the collection efficiency of 8.8 W/m 2 , which is 1.43 times larger than the previous record of 6.2 W/m 2 [10]. The threshold solar power of about 220 W is measured in the focal zone.…”

“…Since then, researchers have been improving constantly the solar laser performance [2][3][4][5][6][7][8][9][10]. The most-widely used Nd:YAG single-crystal material has been demonstrated as an excellent material under solar pumping because of its superior thermal conductivity, high quantum efficiency and mechanical strength characteristics compared to other host materials [6][7][8][9][10]. Significant solar laser collection efficiencies have been achieved by end-pumping small diameter Nd:YAG single-crystal rods [6].…”