STARK SPECTROSCOPY USING THE WATER VAPOR LASER

A far-infrared (FIR) water vapor $(H_{2}O/D_{2}O)$ laser has been developed to perform laser Stark spectroscopy. The FIR laser has beer modified from an existing HCN/DCN laser system and consists of a 4 m long, 10 cm diameter laser cavity with copper reflectors against its ends. The active medium is a $H_{2}O:H_{2}$ or $D_{2}O:D_{2}$ gas mixture. CW laser oscillations at $\\lambda = 118.6 \\mu m$ for $H_{2}O$ and $\\lambda = 107.7 \\mu m$ for $D_{2}O$ have been observed. A reliable output power of 25 mW with stable plasma and a good signal to noise (S/N) ratio has been achieved for both laser lines. The laser Stark spectrum for $CH_{3}OH$ has been observed for the first time up to 50000 V/cm using the $H_{2}0$ and $D_{2}0$ laser lines.