A potential method to control thermal distribution in a solid state heat capacity laser

摘要

Approximate formulas of transient temperature and stress distributions in the slab of a two-sided pumped heat capacity laser (HCL) were attained by solving the heat diffusion equation. The thermal effects in the slab HCL were taken into consideration. By finite element analysis, the transient temperature and stress distributions in the slab medium were simulated with various boundary conditions, and the ANSYS simulations showed that when the pumping beam aperture was less than the pumping area, the peak thermal stress of the slab would increase to 80MPa. Then a new method for reducing thermal gradients between the outer surface of the slab and the internal portions in the slab was proposed, that was the temperature of the outer surfaces of the slab to be adjusted during the lasing stage for a HCL. This method is helpful to reduce the thermal peak stress to 40MPa. It not only provided a compensation for thermal gradients resulting from the limitation of the beam aperture during the pumping stage, but also further improved the output power and the beam quality. Our simulations are meaningful for designing a SSHCL especially the thermal management system in a SSHCL.