Five-Ce:Nd:YAG-rod solar laser approach with TEM₀₀-mode collection efficiency of 51.7  W/m²

One of the major goals of solar-pumped lasers is to improve T E M ₀₀-mode collection and conversion efficiencies. Several studies have explored multi-rod designs with the aim of enhancing laser output and thermal management by distributing the absorbed solar energy across multiple rods. In this work, we introduced a concept comprising four Fresnel lenses with a total collection area of 3.14m ² and four aspherical lenses, which concentrated the sunlight into a water-flooded cylindrical cavity housing five side-pumped Ce:Nd:YAG rods. A beam-merging scheme was also proposed to generate a single output beam. Simulations performed with Zemax and LASCAD demonstrated that this configuration could produce a total T E M ₀₀-mode laser output of 162.3 W. The corresponding collection efficiency reached 51.7W/m ², with a solar-to-laser power conversion efficiency of 5.44%, representing improvements of 3.13 and 2.64 times, respectively, compared to the record experimental results from a system using a single Ce:Nd:YAG crystal and a Fresnel lens. Moreover, even when compared to a more complex seven-rod configuration, both efficiencies exhibited a 1.50 times increase.