SOA Model and Design Guidelines in Lossless Photonic Subsystem

We propose a new practical analytical model to calculate the performance of amplitude-modulated systems, including semiconductor optical amplifiers (SOA). Lower and upper-performance bounds are given in terms of signal quality factor (Q) concerning the input signal pattern. The target is to provide a design tool for gain elements included in photonic integrated circuits (PIC) to compensate for their insertion loss. This subject is a critical issue, for example, in the arrays of optical transmitters with silicon photonics modulators used for interconnection applications. Due to implementation limitations, the design of an SOA embedded in a PIC is considerably different with respect to the use of SOAs as line amplifiers in optical networks. SOA amplified spontaneous emission (ASE) and gain saturation effects have been included in the model, together with the input signal extinction ratio and the receiver electrical filter. Each degradation effect provides its own contribution to the signal integrity in terms of signal-to-noise ratio (SNR) or inter-symbol interference (ISI). The model shows that the SOA operation at low extinction ratios, typical in optical interconnect applications, is substantially different from the operation at higher extinction ratios used in transport networks. The model is validated through numerical simulations and experiments. Finally, two examples are provided for dimensioning a PIC system and optimizing the SOA parameters

New Advances in Semiconductors

New Advances in Semiconductors brings together contributions from important researchers around the world on semiconductor materials and their applications. It includes seven chapters in two sections: “Calculations and Simulations in Semiconductors” and “Semiconductor Materials.” The world will emerge different after the social and economic reorganizations caused by the COVID-19 pandemic and will be even more dependent on semiconductors than ever before. New Advances in Semiconductors is a book that brings together the contributions of important researchers around the world and is able to give an idea about the different characteristics of semiconductor materials and their applications. There is a section dedicated to theory, calculations and logic and another dedicated to the development and characterization of semiconductor materials of great future interest. I really hope that this book will help to spread knowledge about this research field to other researchers and students working in this area or even to those interested in starting their more advanced studies

Wavelength reconfigurability for next generation optical access networks

Next generation optical access networks should not only increase the capacity but also be able to redistribute the capacity on the fly in order to manage larger variations in traffic patterns. Wavelength reconfigurability is the instrument to enable such capability of network-wide bandwidth redistribution since it allows dynamic sharing of both wavelengths and timeslots in WDM-TDM optical access networks. However, reconfigurability typically requires tunable lasers and tunable filters at the user side, resulting in cost-prohibitive optical network units (ONU). In this dissertation, I propose a novel concept named cyclic-linked flexibility to address the cost-prohibitive problem. By using the cyclic-linked flexibility, the ONU needs to switch only within a subset of two pre-planned wavelengths, however, the cyclic-linked structure of wavelengths allows free bandwidth to be shifted to any wavelength by a rearrangement process. Rearrangement algorithm are developed to demonstrate that the cyclic-linked flexibility performs close to the fully flexible network in terms of blocking probability, packet delay, and packet loss. Furthermore, the evaluation shows that the rearrangement process has a minimum impact to in-service ONUs. To realize the cyclic-linked flexibility, a family of four physical architectures is proposed. PRO-Access architecture is suitable for new deployments and disruptive upgrades in which the network reach is not longer than 20 km. WCL-Access architecture is suitable for metro-access merger with the reach up to 100 km. PSB-Access architecture is suitable to implement directly on power-splitter-based PON deployments, which allows coexistence with current technologies. The cyclically-linked protection architecture can be used with current and future PON standards when network protection is required

Lossless ROADM by Exploiting low gain SOAs in fronthaul network

SOA gain blocks are enabling components to realize lossless mini-ROADMs based fronthaul optical access ring networks. The impact of cascaded SOAs on WDM (12X25Gb/s) signal quality is investigated through simulation modelling and experimental validation