Analysis of Vase Shaped Pumping Cavity for Solar-Pumped Laser

Although sunlight is a promising renewable energy source, the light is incoherent and difficult to use directly. Therefore, a solar-pumped laser, which directly converts sunlight into coherent laser light of, is a promising technology. A solar-pumped laser collects sunlight into the laser medium to realize laser oscillation. In order to realize an efficient solar-pumped laser system, it is necessary to design a pumping cavity that absorbs maximal sunlight into the laser medium with minimal thermal shock. In this research, the pumping cavity shape was studied using a numerical ray tracing simulation. As a result, it was found that a cone shaped pumping cavity can be expected to improve the absorption rate by approximately 30% over a cylindrically shaped pumping cavity. Furthermore, the absorption power density distribution can be flattened by a vase shaped pumping cavity, while maintaining the same absorption efficiency. The vase shaped pumping cavity has almost half the dispersion of the absorbed power density in the laser medium when compared with the cone shaped pumping cavity.