Experimental investigation of femtosecond laser-induced ultra-fast phase-change in crystalline silicon
The ablation of crystalline silicon by ultra-short laser pulses is studied experimentally. A pump-and-probe
experiment is implemented in a collinear arrangement, utilizing a time-delayed frequency doubled probe beam
for in situ reflectance measurement and ultra-fast microscopy observation. For the pump beam fluence ranging
from 0.4 to 4.6 J/cm2, the reflected images show evidence of lateral plasma expansion. The energy deposited in the plasma is estimated on the basis of spherical explosion theory utilizing shock front measurement provided by shadowgraph images taken at elapsed times in the order of 10 ns range.