Measurement of thermal lensing in GaAs induced by 100-W Tm:fier laser

摘要

We present the characterization of thermal distortion induced in bulk and orientation-patterned GaAs samples by a 100 W narrow linewidth, linearly polarized CW Tm:fiber laser focused to ～150 μm diameter. For a 500-μm thick bulk GaAs sample, the induced thermal distortion is measured using a probe laser beam at 1080 nm and a Shack-Hartmann wavefront sensor (SHWS). We also compare the power dependent induced divergence for 500-μm thick bulk GaAs and 10-mm thick orientation-partnered GaAs (OP-GaAs) samples as they are translated axially through the focus of a 2-μm wavelength Tm:fiber laser beam.