Ultrafast Spectroscopy of Laser-Driven Nanoshocks in Molecular Solids

Abstract

Using a moderate energy picosecond pulse laser, 4 GPa shock waves are reproducibly generated at a high repetition rate in molecular solids. These tiny but powerful shocks are termed “nanoshocks”. Time resolved vibrational spectra with high signal to noise can be obtained using coherent anti-Stokes Raman scattering (CARS). Applications of nanoshocks in research and industry are discussed briefly. Results are presented on a molecular crystal, anthracene, and an energetic material, NTO. The temperature and pressure of the shocked material, and the risetime and velocity of the shock front are determined spectroscopically. Ultrafast material relaxation processes are investigated.