Abstract
An optically-pumped 385-μm D2O laser system has been constructed for the Thomson scattering ion temperature measurement in a Tokamak plasma. Stable single transverse and stable tunable (over ±1 GHz) operation is performed on the pump TEA 9R (22) CO2 laser using a Zn Se etalon temperature-controlled within ±0.01°C. The frequency of the 385-μm D2Olaser can be tuned to the N2O absorption line center at 778. 192 GHz.At 385-μm, maximum output power of 120 kW, and a quantum efficiency as high as 21% are obtained. The saturation broadening with D2O absorption line is for the first time observed using the ±1 GHz tunable 9R (22) CO2 laser. And, pressure broadening coefficient of N2O absorptionline is measured using the ±1 GHz tunable 385-μm D2O Raman laser to be 7.6 MHz/torr.
