Matthew S. Goodman

MONET: multiwavelength optical networking

This paper presents an overview of the multiwavelength optical networking (MONET) program and summarizes its vision. The program objective is to advance, demonstrate, and integrate network architecture and economics, advanced multiwavelength technology, and network management and control to achieve high capacity, reconfigurable, high performance, reliable multiwavelength optical networks, with scalability to national scale, for both commercial and specialized government applications. The paper describes the major research thrusts of the program including network elements, networking demonstration plans, network control and management, and architecture and economics.

The LAMBDANET multiwavelength network: architecture, applications, and demonstrations

A summary is presented of research conducted over the last few years concerning the LAMBDANET multiwavelength optical network. Descriptions are given of some variations, including several applications based on these architectures. Experimental results demonstrate the technological feasibility of this approach. The LAMBDANET design incorporates three basic ingredients: (1) it associates a unique optical wavelength with each transmitting node in a cluster of nodes; (2) the physical topology is that of a broadcast star; and (3) each receiving node identifies transmitting nodes based on the transmission wavelength through wavelength demultiplexing. This network design features full connectivity among the nodes, large nonblocking throughput, data format transparency, and flexible control. The LAMBDANET network is used for both point-to-point and point-to-multipoint applications. >

Optical networking for quantum key distribution and quantum communications

Modern optical networking techniques have the potential to greatly extend the applicability of quantum communications by moving beyond simple point-to-point optical links and by leveraging existing fibre infrastructures. We experimentally demonstrate many of the fundamental capabilities that are required. These include optical-layer multiplexing, switching and routing of quantum signals; quantum key distribution (QKD) in a dynamically reconfigured optical network; and coexistence of quantum signals with strong conventional telecom traffic on the same fibre. We successfully operate QKD at 1310 nm over a fibre shared with four optically amplified data channels near 1550 nm. We identify the dominant impairment as spontaneous anti-Stokes Raman scattering of the strong signals, quantify its impact, and measure and model its propagation through fibre. We describe a quantum networking architecture which can provide the flexibility and scalability likely to be critical for supporting widespread deployment of quantum applications.

HYPASS: an optoelectronic hybrid packet switching system

An architecture is presented for an optoelectronic hybrid packet switching system (HYPASS) for the distribution of multiple-bit-rate broadband services. HYPASS is based on an input-buffered/output-controlled arbitration protocol. The internal routing and interconnection utilizes a passive optical transport network with wavelength-tunable laser transmitters and fixed wavelength receivers. The single-stage multiwavelength optical interconnect provides an internally nonblocking network for large throughput routing of the bit-serial optical signals. An internal optical control network, with fixed-wavelength trouble receivers, sends output port information to the input nodes for arbitration and control. Packet buffer storage and control processing is performed by word-parallel electronic circuitry. The characteristics and device requirements for this design are presented along with results of a performance analysis of the arbitration and control protocol. >

Fast wavelength-switching of laser transmitters and amplifiers

The authors discuss system aspects and describe experimental demonstrations of nanosecond wavelength tuning in laser diode structures. Both tunable transmitters and tunable filters are considered. The dependence of the refractive index on the carrier density in semiconductors is exploited to obtain fast wavelength tuning. Experimentally, switching times of >

A broadband optical multicast switch

We propose a new optical muhicast switching system based on a two-phase contention resolution algorithm This architec ture may simultaneously support packet switching, and circuat channel emulation. It can handle time-multiplexed variable bit rate random access packets and reserved access packets in a single framework that incorporates unicast and multicast switching. We present the overall switch architecture, its optical device requirements, and possible implementation schemes. Performance enhancements through the addition of multiple tracks are discussed which indicate the flexibility inherent in this design. Results of an analysis of the throughput and switch performance are discussed.

Experimental investigation of quantum key distribution through transparent optical switch elements

Quantum key distribution (QKD) enables unconditional physical layer security for the distribution of cryptographic key material. However, most experimental demonstrations have relied on simple point-to-point optical links. In this paper we investigate the compatibility of QKD with reconfigurable optical networks. By performing the first tests of QKD transmission through optical switches, we study if there are impairment mechanisms other than switch insertion loss that impact the sifted and error corrected secret bit yield. Three types of transparent optical switch elements are investigated including lithium niobate (LiNbO/sub 3/), microelectromechanical systems (MEMS), and optomechanical. We show that QKD can be extended beyond point-to-point links to switched multinode architectures including protected ring networks to enhance quantum channel availability.

Acousto-optic tunable filters (AOTFs) for multiwavelength optical cross-connects: crosstalk considerations

Acousto-optic tunable filters (AOTF) have been investigated as a potential basis for multiwavelength cross-connects in optical networks. In this paper, we discuss crosstalk issues, some of which are common to other cross-connect technologies, and some of which are unique to the AOTF, which will determine the suitability of the AOTF technology for this application. In particular we show how the interactions between wavelength channels make the AOTF sensitive to switch architectures, we conclude that significant performance improvements will be required to diminish crosstalk if the AOTF is to be useful in any but small-size cross-connects, even when spare and wavelength dilation are used.

The MONET project-a final report

The MONET project ended in November 1999. Over the five year duration of this project, many significant advances were made in optical networking architectures, components, subsystems, systems, and network demonstrations. In this paper, we report on the major accomplishment of the last year of the MONET project, which was the completion and operation of a transparent, reconfigurable optical network in Washington, DC. This paper describes the network and summarizes experimental results achieved in the first months of operation.

Demonstration of 1550 nm QKD with ROADM-based DWDM Networking and the Impact of Fiber FWM

We demonstrate compatibility of 1550 nm QKD with a MEMS-based ROADM and also show that four-wave mixing resulting from copropagating DWDM signals can become the dominant source of background noise within the QKD channel passband.