High internet communication technology in developing countries

High speed
communications and computations are the main industrial and academic demands.
Optical method is one of amusing alternatives for doing this purpose 1.Fiber Optic
communication provides higher frequency transmission of signals with greater
bit rate and larger data carrying capacity over a long distance. This means of
data transmission is with a lower loss and interference if compared to the
normal copper wire used in the electrical telecommunication systems. Optical
fiber is extensively used in the application of internet communication technology
in developing countries widely due to its feasibility to transmit data over a longer distance 2.In spite of
all these benefits this high speed optical fiber
transmission system face an interruption in the form of GVD, as different spectral components of
the pulse travel at slightly different group velocities, a phenomenon referred
to as GVD that limits the rates in optical
transmission systems 2-3. On the other hand, for long distance data transmission
in optical fiber, nonlinear effects are introduced in the optical fiber that in
turn limits the system performance 4. SPM is one of the relevant nonlinear
effects that dominate the system performance significantly 5-6. SPM effects
observed when the Kerr non-linearity are the result of the pulses own intensity. The GVD which limits the rates in optical transmission systems are responsible
for changes in pulse shape while SPM are responsible for changes of pulse
spectrum. The combination of
linear and
nonlinear effects leads to both the temporal
and spectral changes of the pulse
7-8. The pulse degradation
in the fiber limits the maximum transmission distance and the transmission rate
of the fiber link; hence it is very important to analyze the pulse behavior of
the propagating pulse in the fiber 9. The pulse propagation is modeled using
nonlinear Schrodinger equation (NLSE) 2. The chirp
parameter, C have important role in pulse propagation. A chirp is a signal in
which the frequency increases called up chirp (C>0) or decreases called down
chirp (C>0)
with time 10. The effect
of GVD is included through dispersion parameter that’s related to 

 . If

 > 0, it is called normal dispersion regime
while for

 < 0, it is called anomalous dispersion regime 11. In anomalous dispersion regime compression occurs for the up-chirped pulses, whereas the broadening takes place for the down-chirped pulses. The opposite situation happens for up- and down-chirped pulses propagating in the normal dispersion regime 4.In this paper; we investigate the change in pulse behavior for both up chirp & down chirp values by propagating a Gaussian pulse at normal and anomalous dispersion regime due to the effect of GVD. The non-linear effect SPM has been visualized for different values of fiber length. Then we analyze the combined effect of SPM with GVD in both anomalous and normal regime. The results are compared for different cases. We used our numerical split step Fourier method for solving the pulse propagation equation numerically which takes account the effects of GVD and SPM.