Electro-optic photonic circuits from linear and nonlinear waves in nanodisordered photorefractive ferroelectrics

The work presented in this thesis addresses different aspects of three main physical issue belonging to the eld of nonlinear optics, quantum optics and optical microscopy. We analyze how photorefraction can be used to photoinduced a tapered ber index of refraction patterns in the bulk of nano-disordered crystals, and we observe how these patterns are able to modulate the phase of Gaussian beams converting them to Bessel-Gauss beams, enhancing their depth of eld and their ability to self-heal after an obstacle. These properties suggest the use of Bessel beam in microscopy. In our investigations we proposed and experimentally demonstrated, in turbid media, the idea of using the interference between multiple Bessel beams to generate a light field that is non diffracting, self-healing, but also localized along the propagation axis. Our study on superimposed Bessel beams reveals how the interference between their side lobes has the overall effect of reducing the amount of energy possessed by the beam outer structures, practically enhancing their localization in the radial direction as well as in the axial. At present we are studying how to implement these findings in a light sheet microscope to improve optical sectioning. Also described in this thesis are a number of intriguing experiments carried out on disordered ferroelectrics and their giant response, these including negative intrinsic mass dynamics, ferroelectric supercrystals, rogue wave dynamics driven by enhanced disorder and first evidence of spatial optical turbulence. Lastly, relying on the necessarily reversible nature of the microscopic process, we demonstrate how a single photon is not able to entangle two distant atoms because of conservation laws, clarifying the long standing debate on the nature of single-photon nonlocality and introducing fundamental limitation, in the use of linear optics for quantum technology.