Multimode Fabry-Perot Laser Diodes: Modeling and Simulation of Mode Partitioning Noise in Fibre-Optic Communication Links

Abstract

The FP multimode semiconductor laser has lightened up a new field of optical communication technology in the past two decades. Numerical modeling of its physical behaviours and transient response has been discussed previously in literature, mostly by constructing the multimode rate equations. Rate equations are very helpful in studying and predicting the average photon and carrier transient response and relaxation oscillation. However, their deficiency in statistical photon fluctuation limits the function of describing stochastic power shifted from main mode to other side modes. Therefore, a noise driven model with conjunction of optical fibre and photodiode is built to form an optical communication system in the simulation scope. The multimode nature of FP lasers causes several problems such as mode partitioning noise (MPN), intersymbol interference (ISI), and frequency chirping, among which mode partitioning noise is the most serious of the concern in this discussion. The stereotype analytical measurement of MPN power penalty is based on several assumptions on the received waveform shape and power distribution spectrum, which limits its fields of application and accuracy. This work develops a numerical solution to power penalty due to MPN, and it can be employed to any multimode laser diode models regardless of the received signal shape and power distribution spectrum. In conclusion, the MPN power penalty is a significant profile of evaluating system perform in fibre-optic communication links. It highly depends on shape of power distribution spectrum, number of modes, length of fibre, and pattern of signal waveform.