A time‐resolved x‐ray scattering technique for observation of non‐equilibrium phonons

We have demonstrated a time‐resolved x‐ray diffraction technique for observing nonequilibrium phonons. We have used this technique to observe phonons in α‐quartz at low temperatures. Phonons were generated by direct stimulation of near zone center transverse‐optical phonons using infrared light from a powerful Q switched CO2 laser. We show data taken at a Brillouin zone boundary confirming the presence of nonequilibrium phonons initially generated by the laser and their resulting decay products.