Generation of nanosecond infrared pulses tunable from 2.8 to 16micron by efficient stimulated electronic Raman scattering.

In this work, an improved source of nanosecond infrared pulses tunable from 2.8 to 16micron (3500 to 630 cm sup -1) is obtained by stimulated electronic Raman scattering in cesium atomic vapor. Visible dye laser pulses are shifted with up to 20% quantum conversion efficiency to obtain up to 4 mJ of infrared pulse energy. The infrared energies are several orders of magnitude higher than are obtained in multi-step nonlinear mixing in crystals, and the tuning range is wider than has been obtained by other shifting methods. The improved infrared source may prove useful in transient infrared vibrational spectroscopy at surfaces and in other condensed phase studies of molecular dynamics.