Knowledge Bank

Two tunable diode lasers have been used to measure room temperature Lorentz halfwidths for a number of lines of $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}C2H2, H2O, HDO$, and $H2O2$ in the $1250-1380-cm-1$ region. Both $N2$ and air-broadened halfwidths have been determined for 29 lines in the P and R branches of the $(v4+v5)$ combination band of $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}C2H2$. The measured $N2$-broadened widths agree within 3% with values obtained previously for a few lines using the same $technique.1$ The air-broadened halfwidths are observed to always be less than the $N2$ widths and, on average, we find $\gamma 0(air)=0.97\gamma (N2). N2$- and air-broadened halfwidths have also been derived for a number of lines in the $\nu 2$ bands of $H2O$ and HDO. These values will be compared with previously published results. Dry air has been added to a 50% pure sample of $H2O2$ to determine air-broadened widths for a number of lines in the $\nu 6$ bands.