Knowledge Bank

We have used cavity ring-down spectroscopy to measure pressure-broadening coefficients for several rotational lines in the atmospheric B band of $O2$ at 688 nm. Collisional partners of the $O2$ include $O2$, $N2$, and Ar. Total pressures range up to 2 atm; at that pressure, the self-broadened linewidth is $0.3cm-1$, about twice the laser bandwidth. Comparisons with previous measurements by other techniques will be discussed.