Sub-Doppler Fluorescence Spectroscopy in Thin Gas Cells Pumped with Broadband Radiation

Abstract

The excitation of atoms (molecules) of a rarefied gas by stationary broadband optical radiation in a thin cell, the inner thickness of which is many times smaller than its transverse size, is studied theoretically. The features of optical pumping and transit-time relaxation of atomic particles in such cells open new possibilities for ultra-high resolution spectroscopy. The conditions are analyzed under which narrow high-contrast sub-Doppler fluorescence resonances arise at the central frequencies of spontaneous transitions from optically excited atomic (molecular) quantum levels.