Knowledge Bank

A far-infrared (FIR) water vapor $(H2O/D2O)$ 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 $H2O:H2$ or $D2O:D2$ gas mixture. CW laser oscillations at $\lambda =118.6\mu m$ for $H2O$ and $\lambda =107.7\mu m$ for $D2O$ 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 $CH3OH$ has been observed for the first time up to 50000 V/cm using the $H20$ and $D20$ laser lines.