Studies of polarization dependent magnetic resonances in rubidium vapor for light ellipticity measurement and vector magnetometry applications

We report our investigations on the dependence of magnetic resonance spectrum on the light ellipticity and the polarization angle. A rubidium vapor cell with octade-cyltrichlorosilane (OTS) antirelaxation coating has been used in our experiment to produce narrow linewidth magnetic resonances. We show that excitation using elliptically polarized light can simultaneously produce the alignment and orientation resonances in a Bell-Bloom interaction geometry. We have developed a theoretical model to calculate the resonance spectrum using light with a varying degree of ellipticity. Amplitudes of the alignment and orientation resonances show a strong dependence on the light ellipticity. Our study shows that the duty cycle of light modulation can effectively control the amplitude variations of the alignment and orientation resonances with light ellipticity. We propose that the difference between the alignment and orientation resonance amplitudes can be used for in situ measurement of the light