High-Sensitivity Cavity Ring-Down Spectrometer for High-Resolution Spectroscopy of Atmospheric Gases in the 745–775-nm Region

A new cavity ring-down spectrometer is designed for the near-infrared spectral region from 745 to 775 nm (12 900–13 400 cm−1). A test spectrum is presented for the rovibrational lines of molecular oxygen in a narrow spectral range near 13 165 cm−1. Sensitivity on the order of 1.7 × 10−10 cm−1 is attained.