טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentKatz Omer
SubjectElliptic Incoherent Solitons
DepartmentDepartment of Physics
Supervisor ? 18? Mordechai Segev


Abstract

When a beam of light is propagating in a homogenous linear medium, it tends to broaden during propagation in each of the transverse directions, to which it propagates. This broadening is caused by linear diffraction. Waveguiding is a method to eliminate this broadening. In a waveguide, the propagation behavior of the beam is modified by the total internal reflections from the boundaries of the waveguide. Under conditions of constructive interference between the total internal reflections of the beam, the beam becomes trapped between these boundaries and forms a guided mode.


Self-trapping of an optical beam occurs when a beam of light induces a change in the index of refraction through a nonlinear interaction and forms a waveguide. If the beam is a guided mode of the waveguide that it induced, then the beam traps itself in the medium, and is diffraction-free. When such a beam self-traps in a stable fashion, it is called optical spatial soliton.


In the year 1998, D. N. Christodoulides et. al. predicted  the existence of "elliptic incoherent solitons" in logarithmically saturable nonlinear media. Two years later, E. D. Eugenieva D. N. Christodoulides and M. Segev, predicted the formation of elliptic incoherent solitons in a physical nonlinearity, namely photorefractive saturable nonlinear media. They investigated this new class of solitons by the use of numerical simulations.


This thesis presents the first experimental observation of elliptic incoherent solitons namely, the self - trapping of an elliptic spatially incoherent beams, in photorefractive media. This is the first observation of the phenomenon of elliptic incoherent solitons in any system.