Multilayer gas cells for compact optical frequency standards

We analyze possibilities of ultra-high resolution spectroscopy of atoms (or molecules) in the suggested multilayer gas cell, which is the compact analog of many plane-parallel atomic (molecular) beams and may be used as the basis for new compact optical frequency standards. In particular, cases of unidirectional and counter-propagating spatially separated monochromatic pumping and probe beams (with the same scanned frequency) have been considered. It was shown, that in these situations the effective width of the Doppler-free resonance in absorption of the probe beam in the multilayer cell may be less (up to the factor ≈ 1.554) than the limitary small width of the known “Lamb deep” in the saturated absorption spectroscopy for the corresponding resonant atomic transition in a usual (hollow) gas cell.