HIGH-RESOLUTION SELECTIVE REFLECTION SPECTROSCOPY IN INTERMEDIATE MAGNETIC-FIELDS

We have measured the modifications of frequency-modulated selective re flection spectra of the Cs D2 line recorded with circularly polarized light by a longitudinal magnetic field in the range 120-280 G. The spe ctra recorded with sigma+ and sigma- polarizations were found to be qu alitatively different, but are well described by a theoretical model b ased on the diagonalization of the hyperfine-Zeeman Hamiltonian. The t echnique presented here is a simple way for investigating fully resolv ed complex Zeeman spectra in moderate magnetic fields and may find app lications in the investigation of anisotropies in long-range atom-surf ace interactions.