A Giant Spin-specific Hall Shift in Light by tailoring Pancharatnam phase

Banerjee, Chitram (2015) A Giant Spin-specific Hall Shift in Light by tailoring Pancharatnam phase. Masters thesis, Indian Institute of Science Education and Research Kolkata.

PDF (MS dissertation of Chitram Banerjee (10MS44)) Chitram_Banerjee-10MS44.pdf - Submitted Version Restricted to Repository staff only Download (2MB)

Abstract

Spin Hall shifts of light, observed for oblique incidences of light or metamaterials, have been of recent interest due to their immense applicative prospect. We report the observation of a SH shift for normal incidence on an exotic optical system, an inhomogeneous anisotropic mediumhaving complex spatially varying birefringent structure. The spatial variation of birefringence is obtained by changing the three dimensional orientation of the liquid crystals in a Twisted Nematic Spatial LightModulator (TNSLM) by modulating the pixels with user-controlled greyscale value. We also report the unusual spin-specificity of the shift, as the shift of the beam-centroid only happens for one kind of Circular Polarization, whereas the other variant is unaffected (convention is dependent on the handedness of the TNSLM). The theoretical analysis reveals that the polarization specific variation of Pancharantnam-Berry Phase as a function of the input greyscale, for a large range of greyscale values, explains the nature of the shift in the centroid of the beam.

Actions (login required)

View Item