Analysis of thermal aberrations in a high average power single-stage Ti:sapphire regenerative chirped pulse amplifier: Simulation and experiment

We present a systematic investigation of thermal loading effects in single-stage high average power regenerative chirped pulse amplifiers based on Ti:sapphire. Using finite element analysis (FEA), we compute the temperature distributions, optical path deformations (OPDs), and corresponding thermal focal lengths for a variety of pumping conditions. We experimentally characterize thermal aberrations in a regenerative amplifier using a variety of techniques (interferometry, pump-probe thermal lens power, and M2 analysis). We find excellent agreement between the FEA modeling and experimental measurements of OPDs. Our methods allow us to predict the optimal pumping conditions for minimizing thermal aberrations for a variety of geometries and pumping conditions.