High Brightness Ce:Nd:YAG Solar Laser Pumping Approach with 22.9 W/m2 TEM00-Mode Collection Efficiency

Abstract

A compact side-pumped solar laser design using a Ce:Nd:YAG laser medium is here proposed to improve the TEM00-mode solar laser output performance, more specifically the beam brightness. The solar laser performance of the Ce:Nd:YAG laser head was numerically studied by both ZEMAX® v13 and LASCADTM v1 software. Maximum multimode laser power of 99.5 W was computed for the 4.1 mm diameter, 34 mm length grooved rod, corresponding to a collection efficiency of 33.2 W/m2. To extract TEM00-mode solar laser, symmetric and asymmetric optical resonators were investigated. For the 4.1 mm diameter, 34 mm length grooved rod, maximum TEM00-mode solar laser collection efficiency of 22.9 W/m2 and brightness figure of merit of 62.4 W were computed using the symmetric optical resonator. While, for the asymmetric optical resonator, the maximum fundamental mode solar laser collection efficiency of 16.1 W/m2 and brightness figure of merit of 37.3 W were numerically achieved. The asymmetric resonator offered a TEM00-mode laser power lower than the one obtained using the symmetric resonator; however, a collimated laser beam was extracted from the asymmetric resonator, unlike the divergent TEM00-mode laser beam provided by the symmetric resonator. Nevertheless, using both optical resonators, the TEM00-mode Ce:Nd:YAG solar laser power and beam brightness figure of merit were significantly higher than the numerical values obtained by the previous Nd:YAG solar laser considering the same primary concentrator.