  Light beam carrying spatially varying state of polarization generates space
varying Pancharatnam-Berry geometric phase while propagating through
homogeneous anisotropic medium. We show that determination of such space
varying geometric phase provides a unique way to quantify the space varying
polarization state of light using a single-shot interferometric measurement. We
demonstrate this concept in a Mach-Zehnder interferometric arrangement using a
linearly polarized reference light beam, where full information on the
spatially varying polarization state is successfully recovered by quantifying
the space varying geometric phase and the contrast of interference. The
proposed method enables single-shot measurement of any space varying
polarization state of light from the measured interference pattern with a
polarized reference beam. This approach shows considerable potential for
instantaneous mapping of complex space varying polarization of light in diverse
applications, such as astronomy, biomedical imaging, nanophotonics, etc., where
high precision and near real-time measurement of spatial polarization patterns
are desirable.
