Knowledge Bank

A-doublet splittings have been measured with Doppler-limited resolution in the overtone vibrational band of NO for J up to 28.5 using a tunable laser difference-frequency spectrometer. A precision of $\sim 5\times 10-5cm-1$ has been achieved fox most of the splittings by computer fitting a Gaussian doublet profile to the digitized absorption data. An improved set of A-doubling parameters for the v = 2 level has been obtained as compared to previously measured constants of the $1\leftarrow 0$ fundamental band of NO and for assessment of the recently reported A-splittings in the $2\leftarrow 1$ ``hot” band.