Tunable diode laser measurements of air- and N2-broadened halfwidths in the nu2 band of D2O

The first experimental measurements of air- and N2-broadened halfwidths of single lines in the nu2 band of D2O were obtained at room temperature, using a semiconductor tunable diode laser operating in the 1250-1340/cm region. The difference observed between air- and N2-broadened halfwidths may be attributed to the different quadrupole moments of the perturbing gas constituents. It is noted that both the airand N2-broadened halfwidths for the two ortho-para doublets are the same, within the present experimental uncertainties.