Abstract :
In fiber-optic networks, the Wavelength Division Multiplexing (WDM) technique
is used to combine several optical signals with different wavelengths to be transmitted on
one same fiber-optic cable, in order to save the number of channels used. Dense
Wavelength Division Multiplexing (DWDM) is a development of WDM, which has narrow
channel spacing, allowing it to transmit more wavelengths for long-distance transmission.
In addition to the advantages it has, DWDM also has weaknesses, one of which is the
nonlinear effect, which can worsen the performance of a system when transmitting
information signals. One of the causes of this effect was due to the non-linearity of the fiber
optic medium. The parameters used are 2 dBm and 4 dBm, 40 Gbps bitrate with 8 channels,
the distance used is 100 km, with channel spacing of 0,4 nm and 1,6 nm, and with the
addition of EDFA optical amplifier. In this study the parameters analyzed were Q-Factor
and BER. From the simulation results, the FWM effect greatly affects the performance of
the DWDM link because Q-Factor results with small power and small channel spacing can
not produce a standard Q-Factor value. However this is corrected by varying the channel
spacing with the larger one, if using 2 dBm power and 0,4 nm channel space on the 8
channels then the maximum value of Q-Factor obtained is only 4.2809, but if varied with
channel space 1,6 nm Q value -Factor meets the standard ie 7,85061.
Keyword: DWDM, FWM, Q-Factor, BER, Optisystem.