Intracavity laser spectroscopy with a semiconductor disk laser-pumped cw Cr2+ : ZnSe laser

Absorption spectra of the air have been measured near 2.31 μm using intracavity laser spectroscopy with a semiconductor disk laser-pumped cw Cr²⁺ : ZnSe laser. It is shown that, at lasing times of at least 3 ms, the sensitivity of the laser to intracavity absorption increases. This allows one to reach an effective path length of 900 km and enables detection of weak lines with absorption coefficients down to 1 × 10^-9 cm^-1.