Thermal Effects On Solid State Heat Capacity Laser Output Characteristics

Thermal effect is a fundamental issue for a high power solid state heat capacity laser. The heat capacity operation mode is one way to partially eliminate the thermal effect of a high average power laser.While the temperature of laser medium rises, the effect of heat is instantaneously changing. The thermal effect in a solid state heat capacity laser was researched indetail in this paper, which includes:1. The background and status of solid state heat capacity laser(SSHCL) were summarized. The key scientific and technological issues in SSHCL were analysed.2. Based on the actual pump energy deposition, the temperature and thermal stress distribution in gain medium of SSHCL were researched by means of 3D heat transfor codes and experimental measurement.3. The physical performance variation of laser medium caused by heating effect when lading was analysed by means of numerical simulations. The calculation result indicated that the heat effect resulted in both non-uniform refractive index and remarkable stress birefringence.4. Energy conversion efficiency of SSHCL was researched. Various losses of energy caused by thermal effect were analysed and quantitatively calculated. The output energy in different cases was measured,which included different pulse durations, repeat frequencies and different resonator configurations.5. Beam quality of SSHCL was also investigated. Active resonator model was bulit.The beam quality in case of 'cold' and 'hot' cavity were simulated. Finally, the near field of the output beam is measured in case of F-P resonator and stable resonator.