Hanle Effect in the Metastable State of 4He Atoms with Arbitrarily Polarized Light

We present theoretical study of the Hanle effect in the metastable state of 4He atoms with arbitrarily polarized light. The orientation and alignment components of the atomic polarization produce resonance signals with different line shapes. The amplitudes and line shapes of Hanle resonance signals have significant dependence on the light polarization. Our results can be used as an efficient method to determine the polarization component of the laser light, which is crucial for atomic physics experiments employing resonant light-atom interactions.