Traveling‐wave sub‐Doppler excited molecule energy transfer spectroscopy

A general formulation of traveling‐wave sub‐Doppler excited molecule energy transfer spectroscopy is presented. The line profile analysis is applied to that determined experimentally for the R(22) $ν3$ HCN transition. $Pn$ the noise equivalent power of the detector is demonstrated to be $⩽10−12 W.$ Finally, the technique is applied to resolve the $KsR(7) ν1$ transition head in $NH3.$