Picosecond infrared vibrational photon echoes in a liquid and glass using a free electron laser

The first infrared vibrational photon echo experiments conducted in a liquid and a glass are reported. The experiments were performed on the CO stretching mode of tungsten hexacarbonyl at 5.1 \ensuremath{\mu}m (1960 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$) in 2-methyltetrahydrofuran over the temperature range 300 to 16 K using picosecond pulses from the free electron laser at Stanford University. In addition, the first vibrational population relaxation measurements spanning a temperature range that takes a system from a liquid to a supercooled liquid to a glass are reported.