Heat distribution analysis of LD end-pumped YAG/Er:YAG/YAG composite laser ceramics

Focusing on LD end-pumped YAG/Er:YAG/YAG composite laser ceramics, this work explores the heat distribution influenced by thickness bonding of YAG and doping concentration of erbium. Simulation results indicate that extending thickness bonding of YAG beyond 3 mm provides limited additional cooling. Optimizing thickness bonding of YAG, particularly with a longer incident end compared with the exit end, significantly reduces internal temperature rise and minimizes end-to-end temperature gradients. Additionally, the gradient doped composite ceramics exhibit superior thermal performance over the uniformly doped ones, demonstrating lower photothermal power density and improved temperature uniformity along both the z axial and the radial directions. These findings underscore the effectiveness of composite laser ceramics in mitigating the thermal loads, offering a viable pathway for advancing high-power structured all-solid-state lasers.