Study Of Optical Interconnects Technologies In Large-Scale Computing Systems

The first decade of the twenty-first century has witnessed the debut of the new technical era—Computing Era. This new era features with increasing embedded intelligence in everyday objects and ubiquitous cloud services, which are all supported by the large-scale computing systems. With the continued advancements in performance of the microprocessors and the emergence of multiprocessors (CMP), the future computing systems are eventually challenged by the communication bound systems, where networking bandwidths become scarce resource, energy consumption of networking infrastructure has become the key issue and the performance of interconnection networks is fundamentally constrained by the underlying electronic technologies. At the same time, the commercial deployments of optical technologies have gone through telecom, datacom and currently entered the computercom, which features with increasing integration of optics with decreasing cost, decreasing power and increasing density.In order to overcome the interconnect bottleneck in large-scale computing systems, the thesis primarily emphasizes on three issues, which include the optical interconnects architectures and testbed, optical interconnects technologies based on silicon photonic device as well as the optical burst switch networking technologies supporting streaming media applications. Through testbed experiment and simulation, we have verified the feasibility of optical interconnection technologies and related mechanisms.The main works of this thesis are summarized as follows:1. We propose a ubiquitous end-to-end optical interconnection architecture featuring a configurable optical switching platform and a network agnostic optical network interface card (O-NIC). With the prevailing and scaling of cloud-based applications, the design of next-generation datacenter networks should take considerations into three main requirements, which are full bisection bandwidth capability, network bandwidth flexibility and low power consumption. Firstly, a modular optical switch fabric prototyping platform is designed and implemented to support technologies enabling diversified switching speeds and switching functionalities. A4×4switching architecture is designed with this platform, showing the ns-scale switching speed and50.7-ns total switching delay.1-Tb/s/port optical packet switching by this configured4×4optical platform is also demonstrated and bit-error-rate measurements indicate error-free transmission for all wavelengths with over4-dB input power dynamic range. A wavelength reconfigurable optical packet-and circuit-switching testbed is also constructed and experimentally verified by utilizing this optical switching platform. Secondly, an optical network interface card capable of bridging the gap between the computing systems and optical networks is developed and high-definition video streaming through this end-to-end optical system is also demonstrated. We also demonstrated a network interface to adapt the streaming services from Wimax clients. Lastly, a cross-layer-enabled optical network node for monitoring and addressing multiple impairments is proposed. Real-time monitoring and reactivity to two impairments (e.g. OSNR, PMD) via dynamically switched wavelengths and lightpath restoration are successfully shown.2. We investigate the optical interconnects technologies based on silicon photonic microring resonators. Firstly, we experimentally characterize the device which shows very high passband bandwidth (70-GHz of3-dB passband bandwidth), wavelength selection, very fast (1.46-ns and1.3-ns of rise and fall time for through port,1.71-ns and0.87-ns for drop port) and multiwavelength switching capability. Secondly, we experimentally demonstrate switching of a40-Gb/s differential-phase-shift-keyed (DPSK) signal through a coupled silicon photonic microring switch. Packetized transmission of the40-Gb/s DPSK signal is achieved with power penalties of0.6-dB and2.4-dB for through port and drop port signals respectively. Furthermore, we experimentally investigate the phase response of the coupled microrings. Thirdly, we present a broadband packet-switching node that utilizes silicon photonic technology. The node design uses a silicon microring for switching functionality, leverages in-flight header processing for arbitration, and has a tunable driving circuit for thermal-effect mitigation. We experimentally demonstrated an error-free routing of10-Gb/s wavelength-striped packets with lengths of up to1536-ns. Lastly, we proposed and demonstrate a hybrid optical packet and wavelength selective switching platform for high-performance data center networks. This architecture based on cascaded silicon microrings and semiconductor optical amplifiers (SOAs) supports wavelength reconfigurable packet and circuit switching, and is highly scalable, energy efficient and potentially integratable.3. We investigate optical burst switch networking technologies supporting streaming media applications. Firstly, in order to efficiently support high definition video clip (HDVC) services over optical networks, we propose the HDVC over optical burst switching (OBS) network and time-based assembly with advance reservation to guarantee smooth transmission of video services over this network. We experimentally demonstrate100%"excellent" of performance of HDVC transmission assisted with this novel scheme. Secondly, performances of transport layer protocols (UDP and several favors of TCPs) are experimentally investigated over OBS testbed with Burst Retransmission (BR). Experimental results show that BR is suitable for UDP when the delay caused by retransmission is still acceptable for applications, but is not suitable for FAST-TCP. Lastly, a novel contention-aware offset-time allocation mechanism (CA-OAM) is proposed to avoid burst contention in the intermediate nodes of LOBS architecture. Simulation results show that CA-OAM help to keep burst loss probability lower than10-3in LOBS network and the corresponding delay is still lower than simple JET-OBS.