A study of quantum interference & entanglement with negative optics

Geometrically decorated two-dimensional (2D) discrete surfaces can be more effective than conventional smooth reflectors in managing wave radiation. Constructive non-specular wave scattering permits the scattering angle (beta) to be other than twice that of incidence (alpha). This result in gross violations of the law of reflection, and significant fraction of the alpha, beta phase space becomes accessible. A wide range of novel reflective behaviors ensues; including the phenomenon of negative reflection were energy transport remains on the same side of the normal.;We experimentally demonstrate the concept with measurements on a one-dimensionally periodic system (grating) where the relation alpha = cos-1[ Z(beta,kappa)] holds; Z is shown to be a function of the diffractive index parameter (kappa) and the two angles alpha and beta. Excellent agreement is found between experimental data and theory.;The potential utilization of diffraction interference is immense. Our work indicates that diffraction interference processes can also give rise to entangled photon pairs. If we could diminish the intensity as low as possible, ideally one photon at a time, we can design experiments to test how these diffracted photons are entangled based on the Michelson interferometer and Lloyd's mirror.