Simulation of solid-state lasers with composites and ceramic crystals

摘要

Composite, core-doped, and ceramic crystals are used to reduce the thermal lensing effect in laser crystals. An accurate simulation of laser resonators is needed to find optimal doping structures for a required laser. Also simulation helps apply these crystals efficiently, fn this work, results of simulations performed on resonators containing core-doped Nd:YAG ceramic crystals with radial dependent doping concentration, and composite crystals with different layers of doping concentration are presented. The absorbed pump light in crystals is simulated using the ray tracing algorithm. The thermal lensing effect has been computed by the finite element analysis of the temperature and deformation. The dynamic mode analysis (DMA) was used to compute the laser beam quality and output power. The DMA solves rate equations separately for each Gauss mode. It also calculates population inversion by solving rate equations on finite volume grids. This approach yields a few thousands of rate equations for population inversion on the finite volume grid. The advantage of this method for both mentioned crystals is that different decay rates can be associated to regions with different doping concentration. Simulation results have shown that sophisticated laser crystals are able to reduce thermal lensing effect and increase beam quality.