Keywords: alkali atoms, selective reflection, nanocell, magnetic field.

A number of magneto-optical processes running at interaction of a narrow-band laser radiation with atomic vapors are adapted in laser technology, metrology, problems of quantum communications, etc [1,2]. That’s why the detailed studies of atomic transitions in external magnetic fields is of high importance. As it is known, the energy levels of atoms undergo frequency shifts and changes in their transition probabilities in an external magnetic field B[1,2].Recently we have shown that the selective reflection of a laser radiation from an interface of dielectric window and atomic vapor confined in a nanocell with a thickness of a ~300nm is a proper tool for atomic spectroscopy [1-4]. The real-time derivative of SR signal (dSR), where each frequency position of the recorded peaks coincides with the atomic transition one, is used and provides a 30 – 60 MHz spectral resolution [3-5]. Below by selective reflection method and a nanocell use the high resolution study of atomic transitions of  Rubidium, Cesium and Potassium will be presented. The comparison of dSR with other sub-Doppler methods such as saturated absorption will be discussed. Possible applications will also be shown.

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[2] M. Auzinsh, D. Budker, and S. M. Rochester, Optically Polarized Atoms: Understanding  

      of Light–Atom Interactions  (Oxford Univ. Press, Oxford, 2010).

[3] A. Sargsyan et al, JETP Lett.104, 224 (2016).

[4] A. Sargsyan, A. Papoyan, I. G. Hughes, C. S. Adams, D. Sarkisyan,  Opt. Lett. 42, 1476  

      (2017).

[5] A. Tonoyan et al , EPL 121, 53001 (2018).