ROTATIONALLY RESOLVED ABSORPTION OF $O_2$ IN THE VISIBLE AT 90K

Abstract

The atmospheric red bands of molecular oxygen due to b$^1\sum_g^+$$\leftarrow$$X^3\sum_g^-$ magnetic dipole electronic transition have been obtained using the phase shift and pulsed cavity ring down technique. A low temperature cell was designed and adapted to the CRD experiment to measure absorption bands at any temperature between 10 K and 298 K using liquid He or liquid $N_2$ as cryogens. The spectra were obtained at room temperature and at 90 K. The rotationally resolved spectra of the (0,0) vibration band, A-band, at 762nm and the (2,0) vibration band, $\gamma$-band, at 628nm were obtained and compared with the simulated spectrum. This information was used to confirm the temperature of the cell.