non linearities

[mani]

i have a question..for example..In a WDM system we have three lightpaths on wavelengths (w-1), (w) , (w+1), ..let w be the reference wavelength..assuming equal transmission power for the three lightpaths, what will be cross phase modulation noise induced on w if all three lightpaths having 10gbps data rate travel over a same link ( distance 100 kms) on a SMF…
Please explain how it can be done using optisystem..
thankxx alot

[Damian Marek]

Hi Mani,

The amount of introduced noise depends on a number of details of the design (power levels, spacing of the signals, overlap in time). We have a great tutorial and overview of the XPM effect at the following link though that could probably explain it better than I could:

Effects of Cross Phase Modulation (XPM) and Four-Wave Mixing (FWM)

Let me know if there is anything else you are having trouble with!

[mani]

Hi Damian..
thanxx for the reply..i tried to follow the link you have suggested but still not been able to understand..let me put my question in a better way.. Suppose we want to check performance of 8 channel OOK NRZ 10 gbps WDM system..i want to know the Q Factor of any WDM channel when Non Linear noise effects are applied with respect to when non linear effects are disabled..Please consider rest of the factors like power per channel, spacing of signals etc as per ur convenience.. Thanxx once again..
regards..
mani

[Damian Marek]

Hi Mani,

In that case, setup your 8 channel system with one channel (or all of them) hooked up to a BER Analyzer. Run the simulation with the self-phase modulation checked and then run it again without it checked and compare the results. The self phase modulation parameter, which also includes cross-phase modulation, can be found in the Nonlinear tab of the optical fiber component.

Cheers

[mani]

well once again thanxx alot for your reply Damian..i tried alot but dont know how i keep on doing one or the other thing wrong..The self phase modulation box checked/not checked gives me alot of lot of variation in Q factor..i am not sure whether im doing it right and most probably, im doing it wrong ..i will be really really greatful if you can please send me two files..first one having 10 Gbps OOK NRZ or RZ 32 channel WDM system and the second one having 40 Gbps DPSK 32 channel WDM system..further i want to check their Q Factor performance with and without non linear effects…Please help..Thanxx alot..
regards..
mani

[Ajay Vyas]

Hello Mani
I am working on nonlineairities on RoF link. Please let me know how we can analyz the order of nonlinearity when we increase length of fiber & power of laser.

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