Phase transitions induced by femtosecond laser pulse irradiation of indium phosphide

The structural transformation dynamics upon irradiation of single-crystalline indium phosphide with 150 fs laser pulses at a wavelength of 800 nm and with various fluences exceeding the melting or the ablation threshold has been investigated. Optical time-resolved reflectivity measurements were employed using two experimental set-ups to cover timescales up to 400 ns after the pulsed excitation. A fs-resolution pump probe set-up covered the early stages of thermal and non-thermal melting and ablation. A real-time-resolved reflectivity set-up employing a streak camera and a photodiode was used for the investigation of the later stages of the resolidification process. In the ablation regime, the resolidification mechanisms have been analysed.