Violation of Bell's inequality for phase singular beams

We have considered optical beams with phase singularity and experimentally verified that these beams, although being classical, have properties of two mode entanglement in quantum states. We have observed the violation of Bell's inequality for continuous variables using the Wigner distribution function (WDF) proposed by Chowdhury et al. [Phys. Rev. A \textbf{88}, 013830 (2013)]. Our experiment establishes a new form of Bell's inequality in terms of the WDF which can be used for classical as well as quantum systems.Comment: 7 pages, 9 figures and 1 tabl

Correlations in Scattered Phase Singular Beams

We discuss about the correlations present in the scattered phase singular beams and utilize them for obtaining the corresponding mode information. We experimentally generate the coherence vortices using the cross-correlation functions between the speckle patterns and validate them with the exact analytical expressions. We also explore their propagation characteristics by considering their geometry along with their divergence. We utilize the autocorrelation measurements of speckle patterns for obtaining the mode information. Further, we study the correlations present in scattered perfect optical vortices which lead to a new class of coherence functions, Bessel-Gauss coherence functions, and utilized for generating the non-diffracting random fields, i.e. propagation invariant fields. We utilized these correlation functions, which are order-dependent although the speckle patterns are order-independent, for encrypting the information which has higher advantage than normal random optical fields