We utilize the tools already presented in a previous publication [DeSavage, S.A; Gordon, K.H; Clifton, E.M.; Davis, J.P.; Narducci, F.A. J. Mod. Opt. 2011, 58 (21), 2028--2035] to theoretically and experimentally investigate in detail Raman transitions in a sample of laser cooled 85Rb. Using cross-linearly polarized Raman fields, we find that, for an arbitrarily oriented magnetic field, the Raman spectrum consists of up to eleven peaks. However, by judicious choice of magnetic field direction, the spectrum can be reduced to a five peaked spectrum (transverse magnetic field) or a six peaked spectrum (longitudinal magnetic field). We present cases in which the full spectrum can not be thought of as the incoherent sum of the five and six peaked spectra.
We have investigated the two basic types of Hanle fluorescence spectra, distinguished by the direction of observation, from a V-type atom with a
Jg =0\ensuremath{\leftrightarrows}
Je =1 transition excited by a linearly polarized laser. In the absence of a magnetic field to lift the Zeeman degeneracy of the sublevels, the incoherent fluorescence spectrum
GXinc(\ensuremath{\omega}) is dark for all Rabi frequencies, while the incoherent fluorescence spectrum
GYinc(\ensuremath{\omega}) exhibits a single peak for small Rabi frequencies and a Mollow-like triplet for large Rabi frequencies. However, if a magnetic field is applied, the incoherent spectra are composed, in general, of five peaks. When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ \ensuremath{\ll}\ensuremath{\Omega}, the incoherent spectrum
GXinc(\ensuremath{\omega}) has four peaks, while
GYinc(\ensuremath{\omega}) has a Mollow-like triplet, and the integrated area (i.e., the fluorescence intensity) under the spectrum
GXinc(\ensuremath{\omega}) is much less than that of
GYinc(\ensuremath{\omega}). When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ \ensuremath{\gg}:\ensuremath{\Omega}, both incoherent spectra have a two-peak structure similar to that of a two-level atom far off resonance, but the integrated area under the spectrum
GXinc(\ensuremath{\omega}) is much greater than that of
GYinc(\ensuremath{\omega}). When ${\mathrm{\ensuremath{\omega}}}_{\mathrm{B}}$ =\ensuremath{\Omega}\ensuremath{\gg}:\ensuremath{\gamma}, both spectra have a similar five-peak structure, and the same integrated area. The results obtained are interpreted in the dressed atomic state representation. In the strong-field limit, the secular approximation is invoked, and analytical expressions of the resonance fluorescence spectra are derived which demonstrate the dependence of the peak heights and widths of the resonance fluorescence spectra on the intensities of the magnetic and linear polarized laser fields in a more transparent way.
We have theoretically and experimentally studied Raman resonances in multi-level atoms (specifically 85Rb). By varying the relative orientation of the magnetic field with respect to the propagation direction of the Raman fields, we have changed the spectrum to consist of five, six, or eleven peaks. However, the spectrum was not always an incoherent sum of the five and six peak spectra and was not always symmetric with respect to the magnetically insensitive transition (clock transition). Using Ramsey interference, we explored decoherence and noise sources in or system. We discuss potential application to magnetometry.
This paper reports a theoretical study on the transmission spectra of an arbitrarily polarized laser beam through a rubidium cell with or without a buffer gas in Hanle-type coherent population trapping (CPT). This study examined how laser polarization, transverse magnetic field, and collisions with buffer gas affects the spectrum. The transmission spectrum due to CPT and the absorption spectrum due to the level crossing absorption (LCA) were calculated according to the laser polarization. The results show that the LCA is strongly dependent on the transverse magnetic field and interaction time of the atoms with a laser light via collisions with the buffer gas. In addition, the spectral shape of the calculated Hanle spectrum is closely related to the direction between the (stray) transverse magnetic field and polarization of the laser.