Investigation of the Fluorescence Spectra of Cs-Vapor Layers with Nanometric Thickness

The high resolution spectroscopy of nanometric alkali-vapor layers has been made possible through the development of extremely thin cell. We present a detailed comparison of the fluorescence profiles amplitude and width, obtained in the extremely thin cell, both theoretically and experimentally. Experiments are performed on the D_{2} line of Cs-vapor layer with thickness L = mλ, where m = 0.5, 0.75, 1, 1.25. The enhancement rate of the transition profiles width is not growing monotonously, but it is larger for L varying in the interval from L = 0.75 λ to L = λ than that varying in the interval from L = λ to L = 1.25 λ. The used theoretical model, based on the optical Bloch equations is in qualitative agreement with the experimental observations.