Decrease of transit-time broadening of spectral resonances by optical pumping of atoms

We propose the new method of essential decrease of transit-time broadening of Doppler-free absorption resonances on transitions between long-lived quantum levels of atoms (or molecules) of a rarefied gas medium. This method is based on preliminary optical pumping of the ground term of atoms (molecules) by additional radiation which is spatially separated from the recording light beam. The proposed method may be applied in atomic (molecular) spectroscopy of ultra high resolution and also in frequency and time standards.