Multirod approach to enhance solar-to-laser conversion efficiency in the Odeillo solar furnace

Abstract. A multirod solar laser station for the megawatt solar furnace (MWSF) in Odeillo, France, was conceptualized and numerically studied to improve the solar-to-laser power conversion efficiency. 18 heliostats from the 63-heliostat field were selected, and 347 kW of solar power was obtained at its focus. From there, a two-dimensional compound parabolic concentrator further concentrated and redistributed the solar rays toward 11 core-doped Nd:YAG rods, each fixed inside a fused silica flow tube. 11.40 kW of total multimode laser power was calculated, corresponding to a 3.29% solar-to-laser power conversion efficiency. This efficiency value represents an enhancement of 1.70 and 1.26 times over that attained from single-rod solar laser systems in side-pumping configuration tested in Odeillo, France, in which Nd:YAG rods were codoped with Cr3  +   and Ce3  +   ions, respectively. It was also 1.44 times higher than that obtained by a previously proposed side-pumping scheme with a solar flux homogenizer and 12 Nd:YAG rods for the same MWSF.