Intensity measurements and self-broadening coefficients in the γ band of O2 at 628 nm using intracavity laser-absorption spectroscopy (ICLAS)

Quantitative measurements of intensities and widths were made for individual rotational lines of the atmospheric oxygen $\text{b}{}^1\text{Σ}{}_{\mathrm{g}}{}^{\mathrm{+}}\text{(ν′ = 2) ← X}{}^3\text{Σ}{}_{\mathrm{g}}{}^{\mathrm{?}}\text{(ν″ = 0)}$ γ band by using a recently developed, highly sensitive, intracavity laser-absorption spectroscopic technique (ICLAS) at 300 torr m. The total band intensity derived from the line intensities is $\text{1.26 ± 0.05}\text{cm}{}^{\mathrm{?1}}\text{km}{}^{\mathrm{?1}}\text{atm}{}^{\mathrm{?1}}$ (STP). Self-broadening collision coefficients for the ^PP and ^PQ branch lines have been determined from the absorption line width and were found to vary from 0.055 cm^?1 atm^?1 at N″ = 1 to 0.037 cm^?1 atm^?1 at N″ = 27.