Abstract:
Group velocity dispersion (GVD) and third-order dispersion (TOD) have severe
deleterious impact on the system performance at ultrahigh speed optical communication.
GVD results in broadening of the propagating pulse causing inter-symbol
interference between adjacent pulses whereas TOD contributes to the unwanted oscillation
in the leading and trailing edges of the pulse in addition to broadening. In
this thesis, a ber Bragg grating (FBG) based optical ber transmission model that
can compensate for both GVD and TOD is modeled and investigated. Modeling of
FBG is performed by nonlinear coupled-mode equations which is solved by transfer
matrix method. An optimization of in-line dispersion compensation using FBG is also
presented. Dispersion compensating ber (DCF) based optical transmission models
are also numerically investigated and performances are evaluated for comparison. Optical
ber transmission model is simulated by nonlinear Schr odinger equation. The
e ect of GVD and TOD compensation is studied extensively at 160 Gb/s.
Two optical simulation tools have been used in this simulation: the OPTIGRATING
and the OPTISYSTEM. OPTIGRATING is a device simulator software used to
design the FBG for various purposes whereas OPTISYSTEM is an optical communication
system simulator used to measure the performance of the system. FBG is
employed in the transmission line in places where DCF was conventionally used and
the system performance is evaluated for both FBG and DCF based model using OPTISYSTEM
software. In addition to that MATLAB is used to visualize and interpret
the results. FBG based systems are found to be more promising solution of overall
dispersion compensation at ultrahigh speed. Further demonstration of optimization
has showed that dispersion compensation with bi-end con guration using FBG and
NZDSF ber gives even better performance. This analysis might be helpful to design
next-generation high speed and ultrahigh speed optical ber communication system
with better compensation and superior system performance.
