Study of the Rb D 2-line splitting in a strong transverse magnetic field with Doppler-free spectroscopy in a nanocell

Abstract

Atomic transitions of 85 Rb and 87 Rb isotopes in a strong transverse magnetic field with induction of up to 7 kG have been studied experimentally. High spectral resolution is achieved owing to the application of the linear Doppler-free spectroscopy method to a nanometric thin cell with the thickness of L = λ/2 = 390 nm, where λ is the wavelength of laser emission tuned to the resonance with the Rb D 2 -line (λ/2-method). It has been observed that the number of atomic transitions in the transmission spectrum of linearly polarized (π) radiation decreases from 64 down to 20 transitions as the field strength increases above B > 5 kG. Four atomic transitions (two of 85 Rb and two of 87 Rb), which are forbidden in the absence of magnetic field, acquire significant strength in the strong magnetic field. Experimental results are in a good agreement with theory. Several practical applications of alkali-vapor-filled nanometric thin cells have been proposed.

Absorption spectroscopy and Stokes polarimetry in a 87Rb vapour in the Voigt geometry with a 1.5 T external magnetic field

“…This gives rise to characteristic absorption spectra that are highly symmetric [41,54] and reflect only the magnitude of the magnetic field [42]. However, there has been some work [55,56] that makes use of the less studied Voigt configuration where, rather than being parallel, the k vector of the light and the direction of the magnetic field B are perpendicular. The change in geometry results in a change in the atomic transitions permitted by the selection rules [57,58] and thus allows for information not only on the magnitude but also on the direction of the magnetic field to be experimentally observed.…”