Orientational dependence of optically detected magnetic resonance signals in laser-driven atomic magnetometers

We have investigated the dependence of lock-in-demodulated Mx-magnetometer signals on the orientation of the static magnetic field B0 of interest. Magnetic resonance spectra for 2400 discrete orientations of B0 covering a 4π solid angle have been recorded by a PC-controlled steering and data acquisition system. Off-line fits by previously derived lineshape functions allow us to extract the relevant resonance parameters (shape, amplitude, width, and phase) and to represent their dependence on the orientation of B0 with respect to the laser beam propagation direction. We have performed this study for two distinct Mx-magnetometer configurations, in which the rf- field is either parallel or perpendicular to the light propagation direction. The results confirm well the algebraic theoretical model functions. We suggest that small discrepancies are related to hitherto uninvestigated atomic alignment contributions