Evolution of laser damage in indium antimonide(InSb) at 1.06-μm wavelength

Abstract

Evolution of laser damage morphology has been studied in 112 oriented, mirror polished Indium Antimonide(InSb) samples as a function of increasing energy , pulse repetition rate and number of pulses using a Nd:Cr:GSGG laser of 1.06µm wavelength having a pulse width of 20ns. Scanning Electron Microscope(SEM) investigations of the irradiated samples have been done to understand the evolution of damage morphology. Damage morphology is consistent with surface melting and solidification along with an evidence of subsurface overheating. Temperature profiles calculated at different fluence levels confirm substantial subsurface heating. Multiple pulse damage seen at 20Hz with increasing fluence levels is mainly thermal damage. Thermal modeling has been done to explain different morphological features.