Knowledge Bank

The characteristics of a $Co:MgF2$ laser are examined with respect to intracavity laser spectroscopy. This laser can be operated in a CW regime and has the broad tunability range from 1.6 to $2.5\mu$m. Many vibrational and overtone transitions of molecules and radicals appear in this spectral region. Optically pumped by $1.34\mu$m laser radiation, the broadband pulsed $Co:MgF2$ laser has been operated at room temperature. We were able to obtain 1-ms-duration pulses. The IR $Co:MgF2$ laser radiation has been up-converted to visible region and spectrally analyzed by a grating spectrograph. The spectra were recorded by a CCD array. The spectral resolution of the recording was $0.05cm-1$. The intracavity absorption spectra of atmospheric carbon dioxide and water vapor were recorded in the $2.03-2.06\mu$m spectral region. The intracavity absorption spectra of ammonia, methane, ethane, methanol, water vapor, methyl iodide, and transient products of flash photolysis of acetone were recorded in the $2.23-2.25\mu$m spectral region. The linear growth of the intracavity absorption was observed for the generation time values from 0 to at least 1 ms which is equivalent to the detection sensitivity of $3\cdot 10-9cm-1$. Numerous atmospheric trace gases with resolved absorption spectra can be monitored at the ppb-level concentrations (1 part in $109$) with this sensitivity.