טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentRivka Bekenstein
SubjectElectromagnetic Waves in Nonlocal Nonlinear Systems and
in Curved Space
DepartmentDepartment of Physics
Supervisor ? 18? Segev Mordechai
Full Thesis textFull thesis text - English Version


Abstract

Many predictions of General Relativity (GR) are still eluding observation. Consequently, analogous systems offer platforms for emulation experiments, where optical settings play a major role. This thesis presents two approaches to emulated GR effects in optics: a linear and a nonlinear approach. As the research advanced, new ideas for various applications of curved space in photonics, were suggested.

Thus far, all GR emulation experiments demonstrated strictly linear dynamics. However, GR is inherently nonlinear: for example, the curvature of space is induced by masses experiencing this curvature in their own dynamics. First, this thesis presents the first experimental study of nonlinear gravitational effects. This is done by optical wavepackets under the long-range thermal nonlinearity. This system is equivalent to the Newton-Schrodinger model, describing the gravitational self-interaction of quantum wavepackets. It demonstrates gravitational phenomena with wavepackets in the curved space they themselves induce, displaying complex nonlinear dynamics arising from the interplay between diffraction and the emulated gravitational effects.

This thesis also studies electromagnetic wavepackets that propagate in two-dimensional curved space, by confining light to curved surface waveguides. It presents shape-preserving spatially accelerating electromagnetic wavepackets in curved space: wavepackets propagating along non-geodesic trajectories while recovering their structure periodically. This thesis also suggests exploiting curved space ideas for a new class of nanophotonic structures with intricate design in three dimensions, enabling control over light dynamics, through the curvature of the medium in which the light is propagating in.

Finally, the thesis presents wavefront shaping through curved space nanophotonics. To do that a miniature dielectric slab sample with predesigned refractive index that varies according to the curvature of space, is used. This technique is used to construct non-diffracting beams, suggesting that GR can inspire any wavefront shaping in highly tight waveguide settings. Finally, a demonstration of the phenomenon of Einstein Rings, whose prediction dates back to 1936 is presented.