Optical networking

Abstract: Polymer optical waveguide devices will play a key role in several rapidly developing areas of broadband communications, such as optical networking, metropolitan/access communications, and computing systems due to their easier processibility and integration over inorganic counterparts. The combined advantages also makes them an ideal integration platform where foreign material systems such as YIG (yttrium iron garnet) and lithium niobate, and semiconductor devices such as lasers, detectors, amplifiers, and logic circuits can be inserted into an etched groove in a planar lightwave circuit to enable full amplifier modules or optical add/drop multiplexers on a single substrate. Moreover, the combination of flexibility and toughness in optical polymers makes it suitable for vertical integration to realize 3D and even all-polymer integrated optics. In this review, a survey of suitable optical polymer systems, their processing techniques, and the integrated optical waveguide components and circuits derived from these materials is summarized. The first part is focused on discussing the characteristics of several important classes of optical polymers, such as their refractive index, optical loss, processibility/mechanical properties, and environmental performance. Then, the emphasis is placed on the discussion of several novel passive and active (electro-optic and thermo-optic) polymer systems and versatile processing techniques commonly used for fabricating component devices, such as photoresist-based patterning, direct lithographic patterning, and soft lithography. At the end, a series of compelling polymer optical waveguide devices including optical interconnects, directional couplers, array waveguide grating (AWG) multi/demultiplexers, switches, tunable filters, variable optical attenuators (VOAs), and amplifiers are reviewed. Several integrated planar lightwave circuits, such as tunable optical add/drop multiplexers (OADMs), photonic crystal superprism waveguides, digital optical switches (DOSs) integrated with VOAs, traveling-wave heterojunction phototransistors, and three-dimensionally (3D) integrated optical devices are also highlighted.

Abstract: Fiber-optic communication systems form the high-capacity transport infrastructure that enables global broadband data services and advanced Internet applications. The desire for higher per-fiber transport capacities and, at the same time, the drive for lower costs per end-to-end transmitted information bit has led to optically routed networks with high spectral efficiencies. Among other enabling technologies, advanced optical modulation formats have become key to the design of modern wavelength division multiplexed (WDM) fiber systems. In this paper, we review optical modulation formats in the broader context of optically routed WDM networks. We discuss the generation and detection of multigigabit/s intensity- and phase-modulated formats, and highlight their resilience to key impairments found in optical networking, such as optical amplifier noise, multipath interference, chromatic dispersion, polarization-mode dispersion, WDM crosstalk, concatenated optical filtering, and fiber nonlinearity

Abstract: While optical-transmission techniques have been researched for quite some time, optical "networking" studies have been conducted only over the past dozen years or so. The field has matured enormously over this time: many papers and Ph.D. dissertations have been produced, a number of prototypes and testbeds have been built, several books have been written, a large number of startups have been formed, and optical WDM technology is being deployed in the marketplace at a very rapid rate. The objective of this paper is to summarize the basic optical networking approaches, report on the WDM deployment strategies of two major US carriers, and outline the current research and development trends on WDM optical networks.

Abstract: Optical Networking: Principles and Challenges.- Enabling Technologies: Building Blocks.- Local, Access, and Metro Networks.- Single-Hop Networks.- Multihop Networks.- Optical Access Networks.- Optical Metro Networks.- Wavelength-Routed (Wide-Area) Optical Networks.- Routing and Wavelength Assignment.- Elements of Virtual-Topology Design.- Advanced Topics in Virtual-Topology Optimization.- Wavelength Conversion.- Survivable WDM Networks.- Light-Tree: Optical Multicasting.- Traffic Grooming.- Advanced Topics in Traffic Grooming.- All-Optical Impairment-Aware Routing.- Network Control and Management.- Optical Packet Switching (OPS).- Optical Burst Switching (OBS).