Hi Saja,
As I can notice from your attached pictures, you can see the cross-talk effects (i.e., FWM). However, since the level of your signal at the entrance of fiber is very low (about -50 dBm according to your pictures), it will be hard to differentiate clearly the non-linearities that you can have. At the same time, it will be very hard to detect such a low signal at the receiver. By the way, what non-linear coefficient do you consider for your fiber?