Coupling Dynamics of Light in Multi-Core Optical Fibers

Licentiate thesis, 2026

Space-division multiplexing (SDM) has emerged as one of the most promising technologies to meet the ever-increasing demand for data transmission driven by the rapid growth of modern data centers and artificial intelligence. The coupling characteristics of SDM devices, such as coupled-core multi-core fibers, determine the exchange of optical power among spatial and polarization modes, which significantly influence the system performance. Characterizing the coupling dynamics in the frequency and time domains provides fundamental insight into the underlying dynamics of SDM systems.

This thesis focuses on the linear and non-linear characterization of coupling dynamics in coupled-core multi-core fibers. The linear coupling characteristics such as frequency and temporal dependence, directly affect the transfer function governing the propagation of spatial and polarization modes in coupled-core multi-core fibers, whereas nonlinear phenomena, such as wavelength conversion and inter-core crosstalk suppression, play a crucial role in the performance and functionality of SDM systems. In addition, a statistical model has been developed to describe the temporal dynamics of random mode coupling, providing insight into the stochastic evolution and temporal stability of the coupled-core multi-core fiber channels.