Aadil,
yes as Jawad explained SPM and XPM are dependent on many factors.
Be clear that SPM (self phase modulation ) means that the wave will experience a phase change due to its intensity while XPM (cross phase modulation) means that the pulse experience a phase modulation due to other signal intensity. since you do not have other signal so there is no XPM you only have SPM.
if you explain more about your idea we can discuss more.
thanks
Mohamed Abouseif