Giant spin hall effect of light in an exotic optical system

We report a giant enhancement of Spin Hall (SH) shift even for normal incidence in an exotic optical system, an inhomogeneous anisotropic medium having complex spatially varying birefringent structure. The spatial variation of birefringence is obtained by changing the three dimensional orientation of liquid crystal by modulating the pixels with user-controlled greyscale value. This polarization dependent spatial variation (in a plane transverse to the direction of propagation of light) of the transmitted light beam (for incident fundamental Gaussian beam lacking any intrinsic angular momentum) through such inhomogeneous anisotropic medium was recorded using an Eigenvalue calibrated Stokes- Mueller imaging system. Giant SH shift was manifested as distinctly different spatial distribution of the recorded output Stokes vector elements for two orthogonal (left and right) input circular polarization states. We unravel the reason for such large enhancement of SH shift by performing rigorous three dimensional analysis of polarization evolution in such complex anisotropic medium. The theoretical analysis revealed that generation of large magnitude of transverse energy flow (quantified via the Poynting vector evolution inside the medium) originating from Spin Orbit Interaction (SOI) in the inhomogeneous birefringent medium leads to the observation of such a large spin dependent deflection of the trajectory of light beam.