Sub-Doppler signals of the hyperfine Cs[62P3/2(Fe)-->62S1/2(Fg)] transition lines in a diode laser-induced retro-fluorescence spectrum at the interface between glass and Cs vapor are, for the first time to our knowledge, experimentally identified and phenomenologically investigated. We propose a qualitative explanation of the origin of the sub-Doppler hyperfine line, based on kinematic effects of the population of the excited 62P3/2(Fe) atoms of the laser-pumped velocity classes confined in the near-field region of the interface. The role played by different relaxation processes contributing to the retrofluorescent atomic linewidth has been characterized. The effective decay rate of the atomic hyperfine level 62P3/2(Fe=5) near a metallic thin film has been measured by using both sub-Doppler retrofluorescence and frequency-modulated selective reflection spectroscopies. For a saturated Cs vapor in a glass cell at a temperature of 130°C, the effective nonradiative relaxation rate of the 62P3/2(F_e=5) energy hyperfine level due to the coupling with a metallic film is estimated to be AFe=5-->Fg=4nf approximately 3.10^8 s^−1.
© 2005 Optical Society of America
Jean-Marie Gagné, Claude Kondo Assi, and Karine Le Bris, "Measurement of the atomic Cs[62P3/2(Fe=5)] hyperfine level effective decay rate near a metallic film with diode laser retrofluorescence spectroscopy," J. Opt. Soc. Am. B 22, 2242-2249 (2005)