William L. Kath

The goal of this research area is the mathematical modeling of high bit-rate fiber-optic communications. We study linear and nonlinear pulse propagation in optical fibers, including solitons. One emphasis has been the application of parametric amplification to optical fiber systems and devices; this work has involved the modelling of experiments performed by Prem Kumar's group at Northwestern.

Most recently, we have been using importance sampling and related methods to investigate the significance of rare events in lightwave transmission systems. Studies have considered polarization mode dispersion (PMD), amplitude and timing jitter in soliton transmission systems caused by amplified spontaneous emission (ASE) noise, and phase jitter in differential phase-shift keyed (DPSK) systems.

 

pseudo eye diagram

Simulated eye-diagram for a 10 Gb/s DPSK system indicating the probability for the received voltage to have a particular value at any given time. The colorbar on right gives the logarithm (base 10) of each color.