Very short far-infrared pulses from optically pumped CH3OH/D, CH3F, and HCOOH lasers using an EQ-switched CO2laser as a pump source

Very short far-infrared (FIR) pulses were generated from optically pumped CH
3
F, CH
3
OH/D, and HCOOH lasers using a
Q
- switched, current pulsed (200 mA, 100 μs), low pressure (20 torr) CO
2
laser as a pump source. Values of 20 ns for the rise time and 50 ns for the decay time of the FIR pulses have been observed. The dependence of the FIR pulse shape parameters, i.e., rise time, decay time, and pulse buildup time, on the width of the pump pulse and the pressure of the molecular gas have been investigated experimentally. Due to the regular pulse shape, high repetition rate (350 Hz), high peak power (≳1 W), and broad spectral range (
\lambda = 100-500 \mu
m), the pulses are very useful for purposes of solid-state and molecular time resolved spectroscopy.