Intensity Fluctuations: A Spectral Approach to Modelling and Controlling XPM in Optical Fibres

Fibre-optic cables carry most of the world’s internet traffic. To meet soaring demand, higher signal power is needed, but this makes the glass behave nonlinearly, so signals interfere and distort data. This thesis investigates the rapid changes in light intensity that carry information. It analyses the frequency composition of these intensity fluctuations as data travels through the glass fibre. The study establishes a direct link between how these intensity patterns evolve and the resulting nonlinear signal distortion. This understanding leads to practical design rules to control these effects, increasing the capacity and speed of global communication networks.