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Space division multiplexing (SDM) has been proposed as the ultimate solution to address the capacity crunch of optical transport networks. The efficient utilization of SDM requires some forms of spatial integration which is expected to bring huge cost savings for the deployment of SDM-based optical networks. Spatially integrated components with different characteristics have been largely explored and demonstrated for the realization of SDM networks, including; transmission media, transceivers with sophisticated digital signal processing (DSP) units, amplifiers, and ultimately optical switching nodes which are the key elements for the realization of transparent optical networks exploiting SDM technologies. As a consequence, in contrast to the currently deployed optical networks based on standard single mode fibers (SSMF), the next generation of optical networks exploiting SDM technologies can be realized utilizing various kinds of transmission media and the other corresponding elements. However, due in part to the physical properties of different components, their complexity, and the technology limitations not all of them meet the economic feasibility and a desired level of network-wide performance. Therefore, careful analysis should be done revealing the most appropriate and cost-effective solutions. In this work, we review the recent developments and findings which pave the way for a simplified and efficient implementation of the spectrally and spatially flexible optical networks., Peer Reviewed, Postprint (published version)

In this paper we present a Si-based monolithically integrated triplexer transceiver along with some applications in Passive Optical Networks (PONs). The device can be used to provide an additional channel for TV distribution where three wavelengths are assigned according to ITU G. 983 standard, 1310 nm for upstream voice and data, 1490 nm for downstream voice and data, and 1550 nm for downstream TV distribution, respectively. Moreover, the device can be utilized for PON monitoring by its inherent ability to terminate the supervision channels, e.g. U-band wavelengths (1625-1675 nm). In this way, no extra component is required at the Optical Network Unit (ONU) to filter the monitoring wavelengths and hence no added insertion loss is introduced. Furthermore, when using monitoring technique based on Optical Time-Domain Reflectometry (OTDR), the Rayleigh backscattered and discretely reflected radiation can be detected without additional noise coming from the ONU., QC 20130520

This paper describes recent research activities and results in the area of photonic switching carried out within the Virtual Department on Switching (VDS) of the European e-Photon/ONe Network of Excellence. Contributions from outstanding European research groups in this field are collected to offer a platform for future research in optical switching. The paper contains the main topics related to network scenarios, switch architectures and experiments, with an effort to investigate synergies and challenging opportunities for collaboration and integration of research expertise in the field., QC 20100525

Plug and play optical (PPO) nodes may be used to facilitate the deployment of optical networks. PPO nodes must be able to learn about the signal propagation properties of the surrounding optical fibers and make their wavelength routing decisions based on the collected data. This paper discusses what are the open challenges that must be overcome to provide cost effective and performing ad hoc networking solutions based on PPO nodes., QC 20120306

All-optical packet switched networking is hampered by the problem of realizing viable queues for optical packets. Packets can be buffered in delay lines, but delay lines do not functionally emulate queues from an input-output point of view. In this paper we consider the problem of exact emulation of a priority queue of size K using a switching system comprised of a switch of size (M + 1) x (M + 1), which has one distinguished input for external arrivals, one distinguished output for external departures, and fixed-length delay lines of lengths L-1, L-2, ..., L-M connecting the other inputs and outputs in pairs. We measure the complexity of such an emulation by M + 1. We prove that M >= [log(K - 1)] and present a construction Sigma(M)(m=1) L-m = K = O(root K). We also sketch an idea for an all-optical packet switched communication network architecture based on approximate emulation of priority queues of finite size using switches and delay lines, with erasure control coding at the packet level.

The main activities supported by the contract were research support (primarily travel) for C. Chekuri, B. Shepherd and P. Winkler. Funds were also used to run the Bell Labs Pow Wow workshop which addressed various problems in the field of combinatorial optimization algorithm design. The workshop resulted in fruitful research papers and has sparked other collaborations, which may lead to new results in the future. The contract also supported a 2-week visit by Bill Cunningham who worked with G. Wilfong and B. Shepherd on some generalized coloring problems arising from the Clos-Network switch designs. Some new technical results were enabled by the contract in the areas of All or Nothing Problems, Combinatorial Probability and Generalized Coloring and Optical Networking.

This is the final report for Washington University's Terabit Burst Switching Project, supported by DARPA and Rome Air Force Laboratory. The primary objective of the project has been to demonstrate the feasibility of Burst Switching, a new data communication service, which seeks to more effectively exploit the large bandwidths becoming available in WDM transmission systems. Burst switching systems dynamically assign data bursts to channels in optical data links using routing information carried in parallel control channels., The original document contains color images.

The High Speed Connectivity Consortium (HSCC) created a nation-wide multi-gigabit network, capable of gigabit connections to end user sites, using fiber optic links at OC-48 rates. The consortium provided high-speed access to the network with consumption-based pricing for affordability. The network backbone was provided by Qwest using their national network. Local access was provided by various sources such as power utilities, Competitive local exchange carriers, and other Right-of-Way owners. The network provided high speed connectivity for research in networking architectures, high bandwidth applications, and protocol research. Specifically, the Matisee Project, a joint collaboration between UC Berkeley, LBNL, CMU, MIT, CNRI and USC/ISI utilized the network for remote MEMS design, fabrication and testing/experiments. The network enabled research into why host systems and the TCP protocols have so much difficulty achieving high performance when operating across high bandwidth delay product networks. The network also enabled research and testing into the distribution of Uncompressed HTDV across wide area networks., The original document contains color images.

PHOCI is an optical imaging system that is suitable for both image capture and reception of optical communications data. The system includes a novel image/data capture chip that imbeds a high-speed optical data communications receiver technology into the image capture array of a digital video camera system. In addition to the development of a new image/data capture chip, the system includes the design of a hardware interface that allows the PHOCI system to pass both image and optical communication data through a USB (or similar communications link) to a COTS host computer. In addition to providing the device drivers necessary to communicate with the PHOCI hardware, the system software provides the data structures and graphical user interface (GUI) that allow a system operator to see the camera image along with the location and recent movement vector for communication sources in the image. This phase 1 activity illustrated the technical feasibility of the device and discovered that the technology is commercially feasible, especially for harsh environments that are not normally well suited to electromagnetic communications, such as that found on a factory floor. (12 figures), Topic no. A01-58.

This report explored the manufacturability of an integrated optoelectric device which functions as an optical AND gate and which could be used for computer communications, i.e., an Integrated Teraherz Optical Asymmetric Demultiplexer (I-TOAD). The motivation for such a device is that it might enable high-speed communication where the aggregate bandwidth of the shared media is hundreds of gigabits per second, while the interface to the computer is relatively inexpensive (e.g. 1GHZ CMOS). Our efforts focused on two distinct but related queries: (1) Can a manufacturable I-TOAD be built, and (2) If you could build a perfect I-TOAD, how would you build a computer network using such a device.

The first part of the report discusses both theoretical and experimental achievements in proposed unidirectional and bi-directional self healing inter-office WDM ring networks. Two different WDM schemes of self healing ring architectures were considered: 2-fiber unidirectional rings and 4-fiber bi-directional rings. Both types of ring networks are themselves completely survivable. The second part deals with the development of critical components required for the implementation of proposed OTDM network architecture. Specifically it examines switching characteristics of SOAs when used for external modulation and demultiplexing at both transmitter and receiver ends of a multi-Gb/s OTDM system. The third part of the report describes the overall progress achieved regarding the use of SOAs as extemal analog modulators to replace the use of semiconductor laser diodes otherwise required for direct modulation at the transmitter end of AM-VSB SCM CATV systems.