Spectral Narrowing of Selective Reflection

Although Cojan was the first to observe spectral narrowing in SR, systematic studies started much later (Woerdman and Schuurmans 1975). The reflectivity at a glass-sodium vapor interface near the sodium Di and D2 lines was measured for different vapor densities. At low sodium densities the resolution of the hyperfine doublet splitting clearly indicated a considerable spectral narrowing as compared to the Doppler width. With an increasing sodium density the hyperfine structure of the SR spectrum was smeared out. When the 

The spectral narrowing in SR can be used for investigafions of both the col-lisional broadening and the shift at the center of the absorption line of the vapor (Sautenkov et al. 1981 Akul shin et al. 1982). Both processes are difficult to measure by conventional methods because of strong absorption. SR can be applied also to the study of coherence between Zeeman sublevels (Weis et al. 1992). However, if a gas cannot be considered as rarefied, it is necessary to take into account the effect of a local field (Guo et al. 1994). Also, it should 

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M.F.H. Schuurmans, Spectral narrowing of selective reflection, /. Phys. (Paris) 1976,37,469. 

Woerdman, J. and Schuurmans, M. (1975). Spectral narrowing of selective reflection fi om sodium vapour. Opt. Commun., 14 248 -251. 

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