Laser shortpulse heating: determination of lagging time due to different pulse parameters

The governing equations of energy transport during laser shortpulse heating is solved analytically for heating periods less or comparable to thermalization time of the substrate material. Since the lattice site temperature rise is considerably low in the time domain considered, the diffusional energy term in the governing equation is neglected. The effect of laser pulse shape parameter on the electron and lattice site temperature rise is investigated. It is found that rate of electron temperature rise in the heating period is lower than that corresponding to longer heating periods. The temporal behavior of electron and lattice site temperatures are similar, provided that the rise of lattice site temperature is low, which is in the order of 1.5 K after 4.5 × 10−12 s heating period. The lagging time between electron and lattice site temperature is more pronounced as the pulse parameter (β/γ) increases.