Frequency stabilized Tm-Ho : YAG laser by locking to (HBr)-Br-79 and CO2 transitions at around 2.09 mu m

A diode-pumped Tm-Ho:YAG laser, widely tunable at around 2090 nm, was fabricated and used to perform high-resolution spectroscopy of several molecular absorption lines of HBr and CO2. The laser source was then frequency locked, using the fringe side locking technique, to the H-79 Br P(12) transition at 2097.222 nm and to the CO2 P(22) transition at 2087.844 nm. The obtained laser frequency stabilities evaluated by monitoring the error signal of the control loop were similar to30 kHz root mean square (rms) values, with both the molecular frequency references. Additional frequency stability measurements were performed by monitoring the beat note between two independently stabilized Tm-Ho:YAG lasers. The two-sample frequency deviation of the beat frequency below 200 kHz was measured over different integration times of interest in Lidar and differential absorption Lidar system applications.