High-power tunable 385-μm D2O vapor laser optically pumped with a single-mode tunable CO2 TEA laser

Abstract

We demonstrate a 2‐GHz tunability of the 385‐μm stimulated Raman transition of D₂O vapor optically pumped by the 9R (22) transition of a tunable single‐mode CO₂ TEA laser. Power levels of up to 800 kW in 100‐nsec pulses and conversion efficiency of CO₂ laser energy to D₂O laser energy at 385 μm of up to 0.4% have been obtained with a D₂O oscillator cavity. The TEA CO₂ pump laser, which consists of a grating and étalon tuned oscillator followed by an amplifier chain, produced 25‐J 100‐nsec single‐mode pulses and was tunable ±1 GHz around the 9R (22) line center. The present results indicate that tunable single‐mode pump lasers are necessary in order to optimize high‐power optically pumped laser systems and to produce narrow‐linewidth spectral characteristics.