"Global IP traffic will continue to grow in the foreseeable future. Different applications are driving demand for increased capacity such as cloud based services, video streaming services, and big data.Since 2008, most Internet traffic has originated or terminated in datacenters. As a result, datacenters have experienced unprecedented traffic increases, where datacenter traffic will reach more than 20.6 zettabytes by 2021, i.e., 3-fold increase since 2016. In response to demands to support capacity increases, there are significant worldwide research and commercialization efforts that are being directed toward developing high speed intra- and inter-datacenter optical interconnects (DCIs). Different material platforms are used to build optical transceivers including the silicon photonics (SiP) platform. The SiP platform has the potential to build compact, high yield, high performance, and low cost complementary metal oxide semiconductor (CMOS) compatible transceivers. In this thesis, we explore devices and circuits for optical DCIs. This thesis can be divided into three parts. In the first part, we develop and demonstrate passive and active SiP components which are essential in photonic integrated circuits (PICs) for optical transceivers. The first device is a 3-dB beam splitter based on multi-mode interference (MMI), where we present the device design and wafer-scale experimental results. Then, we include subwavelength gratings into an asymmetric MMI to enable compact, large bandwidth, and different splitting ratios. Using cascaded MMIs, we design a C-band polarization beam splitter for coherent PICs, where we demonstrate the advantages of using a cascaded MMI design in improving the device extinction ratio. Next, we present the detailed design and experimental results of a high yield and low insertion loss polarization splitter and rotator. Different variations of this design are demonstrated aiming at different performance metrics and operating bands. Finally, we present a variable optical attenuator based on a Mach-Zehnder interferometer structure where a substrate undercut is added to the design to enable low power consumption. In the second part, we present PICs for 200 Gb/s and 400 Gb/s intra-datacenter optical interconnects. First, a 4-lane SiP transmitter is demonstrated based on four parallel Mach-Zehnder modulators (MZMs). The crosstalk between the four MZMs is studied using small-signal and large-signal modulation. Driving the four MZMs simultaneously, 400 Gb/s aggregate rate can be achieved using relatively low voltage swing and simple digital signal processing (DSP). Then, we explore 200 Gb/s transmitters based on dual parallel multi-electrode MZMs (MEMZMs) to generate the PAM4 signal optically which results in a better signal to noise ratio compared to the electrical generation. Finally, we exploit the other polarization dimension by demonstrating a dual-polarization transmitter in a stokes vector direct detection experiment. More than 200 Gb/s can be achieved using this transmitter which doubles the capacity used for a classical intensity modulation/direct detection system and renders a better scalable approach for bitrates beyond 400 Gb/s. In the last part, we report system-level demonstrations targeting DCI applications. First, we present a single wavelength and polarization PAM4 transmission experiment using state of the art digital-to-analog converters (DACs), analog-to-digital converters (ADCs), and a lithium niobate MZM. Then, we present the first demonstration of a 400 Gb/s transmitter optical sub-assembly (TOSA) on the coarse wavelength division multiplexing (CWDM) grid. The TOSA performance is studied versus several parameters. Results show that we can achieve more than 600 Gb/s over 20 km of single mode fiber (SMF) without optical amplification"--

Photonic Interconnects for Computing Systems provides a comprehensive overview of the current state-of-the-art technology and research achievements in employing silicon photonics for interconnection networks and high-performance computing, summarizing main opportunities and some challenges.

Current data centre networks, based on electronic packet switches, are experiencing an exponential increase in network traffic due to developments such as cloud computing. Optical interconnects have emerged as a promising alternative offering high throughput and reduced power consumption. Optical Interconnects for Data Centers reviews key developments in the use of optical interconnects in data centres and the current state of the art in transforming this technology into a reality. The book discusses developments in optical materials and components (such as single and multi-mode waveguides), circuit boards and ways the technology can be deployed in data centres. Optical Interconnects for Data Centers is a key reference text for electronics designers, optical engineers, communications engineers and R&D managers working in the communications and electronics industries as well as postgraduate researchers. Summarizes the state-of-the-art in this emerging field Presents a comprehensive review of all the key aspects of deploying optical interconnects in data centers, from materials and components, to circuit boards and methods for integration Contains contributions that are drawn from leading international experts on the topic

Silicon photonics is beginning to play an important role in driving innovations in communication and computation for an increasing number of applications, from health care and biomedical sensors to autonomous driving, datacenter networking, and security. In recent years, there has been a significant amount of effort in industry and academia to innovate, design, develop, analyze, optimize, and fabricate systems employing silicon photonics, shaping the future of not only Datacom and telecom technology but also high-performance computing and emerging computing paradigms, such as optical computing and artificial intelligence. Different from existing books in this area, Silicon Photonics for High-Performance Computing and Beyond presents a comprehensive overview of the current state-of-the-art technology and research achievements in applying silicon photonics for communication and computation. It focuses on various design, development, and integration challenges, reviews the latest advances spanning materials, devices, circuits, systems, and applications. Technical topics discussed in the book include: • Requirements and the latest advances in high-performance computing systems • Device- and system-level challenges and latest improvements to deploy silicon photonics in computing systems • Novel design solutions and design automation techniques for silicon photonic integrated circuits • Novel materials, devices, and photonic integrated circuits on silicon • Emerging computing technologies and applications based on silicon photonics Silicon Photonics for High-Performance Computing and Beyond presents a compilation of 19 outstanding contributions from academic and industry pioneers in the field. The selected contributions present insightful discussions and innovative approaches to understand current and future bottlenecks in high-performance computing systems and traditional computing platforms, and the promise of silicon photonics to address those challenges. It is ideal for researchers and engineers working in the photonics, electrical, and computer engineering industries as well as academic researchers and graduate students (M.S. and Ph.D.) in computer science and engineering, electronic and electrical engineering, applied physics, photonics, and optics.

Integrated Photonics for Data Communications Applications reviews the key concepts, design principles, performance metrics and manufacturing processes from advanced photonic devices to integrated photonic circuits. The book presents an overview of the trends and commercial needs of data communication in data centers and high-performance computing, with contributions from end users presenting key performance indicators. In addition, the fundamental building blocks are reviewed, along with the devices (lasers, modulators, photodetectors and passive devices) that are the individual elements that make up the photonic circuits. These chapters include an overview of device structure and design principles and their impact on performance. Following sections focus on putting these devices together to design and fabricate application-specific photonic integrated circuits to meet performance requirements, along with key areas and challenges critical to the commercial manufacturing of photonic integrated circuits and the supply chains being developed to support innovation and market integration are discussed. This series is led by Dr. Lionel Kimerling Executive at AIM Photonics Academy and Thomas Lord Professor of Materials Science and Engineering at MIT and Dr. Sajan Saini Education Director at AIM Photonics Academy at MIT. Each edited volume features thought-leaders from academia and industry in the four application area fronts (data communications, high-speed wireless, smart sensing, and imaging) and addresses the latest advances. Includes contributions from leading experts and end-users across academia and industry working on the most exciting research directions of integrated photonics for data communications applications Provides an overview of data communication-specific integrated photonics starting from fundamental building block devices to photonic integrated circuits to manufacturing tools and processes Presents key performance metrics, design principles, performance impact of manufacturing variations and operating conditions, as well as pivotal performance benchmarks

Dramatic increases in processing power have rapidly scaled on-chip aggregate bandwidths into the Tb/s range. This necessitates a corresponding increase in the amount of data communicated between chips, so as not to limit overall system performance. To meet the increasing demand for interchip communication bandwidth, researchers are investigating the use of high-speed optical interconnect architectures. Unlike their electrical counterparts, optical interconnects offer high bandwidth and negligible frequency-dependent loss, making possible per-channel data rates of more than 10 Gb/s. High-Speed Photonics Interconnects explores some of the groundbreaking technologies and applications that are based on photonics interconnects. From the Evolution of High-Speed I/O Circuits to the Latest in Photonics Interconnects Packaging and Lasers Featuring contributions by experts from academia and industry, the book brings together in one volume cutting-edge research on various aspects of high-speed photonics interconnects. Contributors delve into a wide range of technologies, from the evolution of high-speed input/output (I/O) circuits to recent trends in photonics interconnects packaging. The book discusses the challenges associated with scaling I/O data rates and current design techniques. It also describes the major high-speed components, channel properties, and performance metrics. The book exposes readers to a myriad of applications enabled by photonics interconnects technology. Learn about Optical Interconnect Technologies Suitable for High-Density Integration with CMOS Chips This richly illustrated work details how optical interchip communication links have the potential to fully leverage increased data rates provided through complementary metal-oxide semiconductor (CMOS) technology scaling at suitable power-efficiency levels. Keeping the mathematics to a minimum, it gives engineers, researchers, graduate students, and entrepreneurs a comprehensive overview of the dynamic landscape of high-speed photonics interconnects.

This book is volume III of a series of books on silicon photonics. It reports on the development of fully integrated systems where many different photonics component are integrated together to build complex circuits. This is the demonstration of the fully potentiality of silicon photonics. It contains a number of chapters written by engineers and scientists of the main companies, research centers and universities active in the field. It can be of use for all those persons interested to know the potentialities and the recent applications of silicon photonics both in microelectronics, telecommunication and consumer electronics market.