Mode-Partition Noise in Semiconductor Lasers

Abstract : The primary goal of this research activity is to understand the range of applicability of different types of lasers to a variety of Electronic Warfare (EW) applications. This work helps by providing a detailed understanding of mode-partition noise (MPN) in multi-mode Fabry-Perot (FP) semiconductor lasers. Mode partitioning in semiconductor lasers describes how the intensities of all longitudinal optical modes fluctuate as they compete with each other for a common injected-carrier population. The results presented in this report include both numerical simulations and experimental measurements. The numerical simulations are based on a noise-driven 21-mode rate-equation laser model, which enables multiple mode partition to be modelled. The formulation of the laser model allows for variation of laser parameters to investigate their effect on mode- partition noise. To the author's best knowledge, only studies with variations of trivial laser parameters have been reported previously. The results in this report go beyond these existing studies in the literature. Experimental measurements are used to verify simulations where possible. The main difficulty in this work is having laser devices with different parameters as in the simulations. In addition, the available laser device operates in different regimes as a function of injected current, making it difficult to extract parameters with good certainty to simulate the device.