  We report on experimental and theoretical investigations of the polarization
dependence of magnetic resonance generated by synchronous optical pumping.
Magnetic resonances with narrow linewidth are generated experimentally using a
rubidium vapor cell with octade-cyltrichlorosilane (OTS) antirelaxation coating
on inner walls. We studied the effect of light ellipticity on the amplitudes
and widths of magnetic resonances by matching the light modulation frequency
with 2 {\Omega}_L (alignment) and {\Omega}_L(orientation) in a Bell-Bloom
interaction geometry, where {\Omega}_L corresponds to the Larmor frequency.
Both 2 {\Omega}_L and \OmegaL resonance amplitudes showed a strong dependence
on the light ellipticity. In addition, we showed that the duty cycle of light
modulation changes the slope of amplitude variations in 2{\Omega}_L and
{\Omega}_L resonances with light ellipticity. As a potential application, we
showed that the difference between 2{\Omega}_Land {\Omega}_Lresonance
amplitudes can be used for in situ measurement of light ellipticity. We also
studied the dependence of 2{\Omega}_L and {\Omega}_L resonance amplitudes on
the polarization angle of linearly polarized light. These amplitudes oscillate
periodically with the polarization angle. We found this oscillatory behavior to
be sensitive to the tilt in magnetic field direction from the polarization
plane. Such a property could be used to realize a vector magnetometer. A
density matrix based theoretical model is developed to simulate the magnetic
resonance spectrum for different light polarizations. Our theoretical model
accurately reproduces the above mentioned experimental observations.
