M.Sc Thesis

M.Sc StudentOskar Dror
SubjectFormation of Similaritons in Bragg Gratings Written in
Passive Fibers
DepartmentDepartment of Electrical and Computer Engineering
Supervisor PROF. Moshe Horowitz
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Optical Similaritons are optical pulses, which are formed in fiber amplifiers with normal group velocity dispersion (GVD). Under certain conditions, an arbitrary seed pulse will evolve into a pulse with parabolic intensity and a linear chirp, which asymptotically approaches a self-similar solution, called similariton. Such pulses have been also studied in passive dispersive decreasing fibers (DDF). The initial seed pulse width was limited in both systems to few ps due to the limited GVD in fibers.

In this work we theoretically demonstrate a novel approach to obtain parabolic pulses, based on pulse propagation in Fiber Bragg Grating (FBG).  FBGs can have a GVD, which is higher by more than 6 orders of magnitude than in fibers. Together with the ability to tailor the FBG properties along the grating, it is possible to obtain parabolic pulses for long pulses with a duration on the order of a nanosecond after propagation through a grating with a length on the order of few meters. This result is important for applications such as nanosecond pulse amplification and compression.