200 S Laurel Ave - Bldg A
Middletown, NJ
Shared Mesh Restoration in ROADM Based Service Velocity Network
Inwoong Kim, Paparao Palacharla, Xi Wang, Qiong Zhang, Daniel Bihon, Mark Feuer, Sheryl Woodward
OFC/NFOEC 2013,
2013.
[PDF]
[BIB]
Optical Society of America Copyright
The definitive version was published in 2012. , Issue NW4I.3, 2013-03-17
{Simulations of shared mesh restoration in a backbone network supporting rapid provisioning show up to 27% fewer regenerators than dedicated protection, plus ~40% increase in capacity. Regenerator site concentration and minimum-regenerator routing provide best results.}
ROADM System for Space Division Multiplexing With Spatial Superchannels
Mark Feuer, Lynn Nelson, Xiang Zhou, Rejoy Isaac, K. Abedin, B. Zhu, D. Marom, G. Cohen, R. Harel
OFC/NFOEC2013 conterence proceedings,
2013.
[PDF]
[BIB]
Optical Society of America Copyright
The definitive version was published in 2013. , 2013-03-17
{A two-span SDM system includes the first ROADM supporting spatial superchannels and the first cladding-pumped multicore-EDFA directly spliced to multicore transmission fiber. For 6x40x128-Gb/s SDM-WDM-PDM-QPSK transmission, BER penalties are <1.3dB in Add, Drop, and Express paths.}
Cost Optimization Using Regenerator Site Concentration and Routing in ROADM Networks
Rakesh Sinha, Angela Chiu, Mark Feuer, Guangzhi Li, Sheryl Woodward, Weiyi Zhang, Balagangadhar G Bathula, Keren Bergman, Robert Doverspike, Peter Magill
DRCN 2013,
2013.
[PDF]
[BIB]
IEEE Copyright
This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in 2012. , 2013-03-04
{The advent of colorless and non-directional reconfigurable
optical-add-drop multiplexers (ROADMs) will enable
flexible pre-deployment of optoelectronic regenerators in future
optical networks. Compared to the current practice of installing
regenerators only when a circuit needs them, pre-deployment
will allow service providers to achieve rapid provisioning and
restoration. The pre-deployed regenerators should be concentrated
in a selected subset of ROADM sites in order to attain high
utilization and to reduce operational costs. We prove that the
resulting optimization problem is NP-hard and present an efficient
heuristic for this problem that takes into account both the cost of
individual circuits (regenerator cost and transmission line system
cost) and the probability of a given circuit request, as well as
the number of regenerator sites. We provide various methods
to reduce the number of regenerator sites, if low probability
demands are allowed to have slightly costlier paths. Specific
network examples show that the proposed heuristic has near
optimal performance under most studied scenarios. We present
results for several different cost models. We have also evaluated
the heuristic for survivable optical networks, in which a second,
disjoint path must be supported for each circuit.}
Simulations of a Service Velocity Network Employing Regenerator Site Concentration
Mark Feuer, Balagangadhar Bathula, Daniel Bihon, Angela Chiu, Inwoong Kim, Guangzhi Li, Paparao Palacharla, Rakesh Sinha, Xi Wang, Sheryl Woodward, Weiyi Zhang
OFC/NFOEC2012 conference,
2012.
[PDF]
[BIB]
Optical Society of America Copyright
The definitive version was published in OFC/NFOEC2012 conference. , 2012-03-04
{We use Monte Carlo simulations of quasi-static traffic growth to study concentration of regenerator sites in dynamic photonic networks supporting service velocity. Idle regenerators can be reduced by >60% compared to unrestricted regeneration sites.}
On Concentrating Regenerator Sites in ROADM Networks
Rakesh Sinha, Angela Chiu, Guangzhi Li, Weiyi Zhang, Mark Feuer, Sheryl Woodward, Balagangadhar G. Bathula, Keren Bergman, Inwoong Kim, Paparao Palacharla
OFC/NFOEC2012 conference,
2012.
[PDF]
[BIB]
Optical Society of America Copyright
The definitive version was published in OFC 2012. , 2012-03-04
{Concentrating optical regenerators in a subset of network nodes provides significant savings. We present a
heuristic for choosing this subset. Our results are within 1 or 2 of optimal in the studied cases.}
Joint Digital Signal Processing Receivers for Spatial Superchannels
Mark Feuer, Lynn Nelson, Xiang Zhou, Sheryl Woodward, Rejoy Isaac, Benyuan Zhu, Thierry F. Taunay, Michael Fishteyn, John F. Fini, Man F. Yan
IEEE Photonics Technology Letters,
2012.
[PDF]
[BIB]
IEEE Copyright
This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in 2012. , Volume 24, Issue 21, 2012-11-01
{We discuss the advantages of spatial superchannels for future terabit networks based on space division multiplexing (SDM), and demonstrate reception of spatial superchannels by a coherent receiver utilizing joint digital signal processing (DSP). In a spatial superchannel, the SDM modes at a given wavelength are routed together, allowing simplified design of both transponders and optical routing equipment. For example, common-mode impairments can be exploited to streamline the receiver’s DSP. Our lab measurements reveal that the phase fluctuations between the cores of a multicore fiber are strongly correlated, and therefore constitute such a common-mode impairment. We have implemented master-slave phase recovery of two simultaneous 112Gbps subchannels in a 7-core fiber, demonstrating reduced processing complexity with no increase in the bit-error ratio. Furthermore, we have investigated the feasibility of applying this technique to subchannels carried on separate single-mode fibers, a potential transition strategy to evolve today’s fiber networks toward future networks using multicore fibers.}
Demonstration of Joint DSP Receivers for Spatial Superchannels
Mark Feuer, Lynn Nelson, Xiang Zhou, Sheryl Woodward, Rejoy Isaac, B. Zhu, T. F. Taunay, M. Fishteyn, J. F. Fini, M. F. Yan
IEEE Photonics Summer Topicals 2012 conference,
2012.
[PDF]
[BIB]
IEEE Copyright
The definitive version was published in 2012. , 2012-07-09
{We report lab measurements of joint digital signal processing of simultaneous 112Gbps links in a 7-core fiber. Strongly-correlated phase fluctuations between the cores permit reduced processing complexity with no increase in the bit-error ratio.}
Advanced ROADM Networks
Mark Feuer, Sheryl Woodward
OFC/NFOEC2012 conference,
2012.
[PDF]
[BIB]
Optical Society of America Copyright
The definitive version was published in OFC/NFOEC2012 conference. , 2012-03-04
{We discuss the growing list of features being proposed for reconfigurable optical add/drop multiplexers (ROADMs), including colorless, directionless, contentionless, and gridless operation. Is �less� always more for network operators?}
Research Highlights: Optical Systems Research at AT&T Labs
Martin Birk, Mikhail Brodsky, Mark Feuer, Patrick Iannone, Peter Magill, Jonathan Nagel, Lynn Nelson, Kenneth Reichmann, Sheryl Woodward, Xiang Zhou
IEEE Photonics Newsletter,
2011.
[PDF]
[BIB]
IEEE Copyright
This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in IEEE Photonics Newsletter. , 2011-07-01
{}
On the Capacity of a Hybrid Broadcast Multiple Access System for WDM Networks
Vinay Vaishampayan, Chao Tian, Mark Feuer
IEEE International Symposium on Information Theory,
2011.
[PDF]
[BIB]
IEEE Copyright
This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in IEEE International Symposium on Information Theory. , 2011-08-01, 10.1109/ISIT.2011.6033967
{Abstract�An information theoretic analysis is presented for
a layered communication system designed for enhancing the
network management capabilities of a wavelength division multiplexed
(WDM) optical network. A theoretical model for the
layered communication system is developed, and is seen to be a
combination of a multiple access and broadcast communication
system. Inner and outer bounds for the capacity region are
derived for both general discrete memoryless model and the
Gaussian model, which provide a complete solution for the
symmetric problem. Comparisons are drawn between the coding
technique suggested by an information theoretic analysis and the
coding method used in a working implementation.}
Looking Backward: 2021-2011 in Lightwave Communications
Mark Feuer
IEEE Photonics Conference IPC2011,
2011.
[PDF]
[BIB]
IEEE Copyright
This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in IEEE Photonics Conference IPC2011. , 2011-10-09
{I present a summary of lightwave communications in the year 2021, reviewing the history of innovations that sustained a decade of capacity growth and unprecedented network flexibility and efficiency. }
Intra-Node Contention in Dynamic Photonic Networks
Mark Feuer, Sheryl Woodward, Paparao Palacharla, Xi Wang, Inwoong Kim, Daniel Bihon
IEEE J. Lightwave Technology,
2011.
[BIB]
{Dynamic photonic networks rely on colorless, non-directional Reconfigurable Optical Add/Drop Multiplexer (ROADM) nodes to enable rapid re-routing of wavelength channels without optoelectronic conversion. We report numerical simulations of the wavelength contention that can occur in such multi-degree ROADM nodes. Intra-node blocking rates and transponder utilization are computed for node designs with and without a client-side fiber cross-connect, and both are compared to results predicted for an ideally contention-free ROADM.}
Bandwidth on Demand for Inter-Data Center Communication
Ajay Mahimkar, Robert Doverspike, Emmanuil Mavrogiorgis, Jorge Pastor, Jennifer Yates, Mark Feuer, Sheryl Woodward, Peter Magill, Angela Chiu
ACM SIGCOMM Workshop on Hot Topics in Networks,
2011.
[PDF]
[BIB]
ACM Copyright
(c) ACM, 2011. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in ACM SIGCOMM Workshop on Hot Topics in Networks , 2011-10-15.
{Cloud service providers use replication across geographically distributed data centers to improve end-to-end performance as well as to offer high reliability under failures. Content replication often involves the transfer of huge data sets over the wide area network and demands high backbone transport capacity. In this paper, we discuss how a Globally Reconfigurable Intelligent Photonic Network (GRIPhoN) between data centers could improve operational flexibility for cloud service providers. The proposed GRIPhoN architecture is an extension of earlier work [34] and can provide a bandwidth-on-demand service ranging from low data rates (e.g., 1 Gbps) to high data rates (e.g., 10-40 Gbps). The inter-data center communication network which is currently statically provisioned could be dynamically configured based on demand. Today's backbone optical networks can take several weeks to provision a customer's private line connection. GRIPhoN would enable cloud operators to dynamically set up and tear down their connections (sub-wavelength or wavelength rates) within a few minutes. GRIPhoN also offers cost-effective restoration capabilities at wavelength rates and automated bridge-and-roll of private line connections to minimize the impact of planned maintenance activities.}
Digital Lightpath Label Transcoding for Dual-Polarization QPSK Systems
Mark Feuer, Vinay Vaishampayan, Vitaly Mikhailov, Paul Westbrook
Optical Fiber Communications Conference, OFC/NFOEC2011, Los Angeles, CA,
2011.
[PDF]
[BIB]
Optical Society of America Copyright
The definitive version was published in proceedings of OFC 2011 (Optical Society of America). , Issue paper JWA28, 2011-03-06
{We introduce digital lightpath labeling for DP-QPSK systems, using novel binary encoding to embed a polarization-shift-keyed subchannel. An integrated inline polarimeter powers a compact label receiver with robust tolerance to polarization rotation in a 40Gb/s demonstration. }
A regression approach to infer electricity consumption of legacy telecom equipment
Steven Phillips, Sheryl Woodward, Mark Feuer, Peter Magill
ACM SIGMETRICS Performance Evaluation Review,
2010.
[PDF]
[BIB]
ACM Copyright
(c) ACM, 2010. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution.
The definitive version was published in ACM GreenMetrics Workshop , Volume 38, Issue 3, 2010-10-10.
{Information and communications technology accounts for
a significant fraction of worldwide electricity consumption.
Given the relentless growth of demand for communications
services, telecommunications providers will need to transition
to more energy-efficient technology in order to limit
their environmental impact. Here we focus on priority-setting
for the transition process. In particular, we introduce a
method for statistically inferring the electricity consumption
of different components of the installed base of telecommunications
equipment, while avoiding the high cost of performing
direct measurements. Our method relies only on
databases of installed equipment in central offices, together
with aggregate electricity consumption per office. It takes
advantage of inter-office variation in installed equipment to
partition per-office electricity consumption by major equipment
type. When applied to a collection of 3,918 central
offices of a major U.S. telecommunications provider, our approach
reveals the (previously unknown) network-wide energy
consumption of each major type of equipment. In particular,
we find that electricity consumption is dominated by
Class-5 telephone switches, which account for 43% of aggregate
consumption, and which should therefore be a primary
target of central office electricity conservation efforts.}
Rejection of inter-label crosstalk in a digital lightpath labeling system with low-cost, all-wavelength receivers
Mark Feuer, Vinay Vaishampayan
2005.
[DOC]
[BIB]
IEEE Copyright
Copyright (1992-2009) IEEE. The IEEE owns the copyright to material that is published by the IEEE. Personal use of this material is permitted. However, permission to reprint / republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Please read the full
IEEE copyright policy.
LightLabel: a Management Tool for Photonic Networks
Mark Feuer, Vinay Vaishampayan
2005.
[PDF]
[BIB]
IEEE Copyright
Copyright (1992-2009) IEEE. The IEEE owns the copyright to material that is published by the IEEE. Personal use of this material is permitted. However, permission to reprint / republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Please read the full
IEEE copyright policy.
Effect of Chip-Level Asynchronism on an Overlay System for Optical Networks
Vinay Vaishampayan, Mark Feuer
2005.
[PDF]
[BIB]
IEEE Copyright
Copyright (1992-2009) IEEE. The IEEE owns the copyright to material that is published by the IEEE. Personal use of this material is permitted. However, permission to reprint / republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Please read the full
IEEE copyright policy.
An Overlay Architecture for Managing Lightpaths in Optically Routed Networks
Vinay Vaishampayan, Mark Feuer
2004.
[PS]
[BIB]
IEEE Copyright
Copyright (1992-2009) IEEE. The IEEE owns the copyright to material that is published by the IEEE. Personal use of this material is permitted. However, permission to reprint / republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Please read the full
IEEE copyright policy.
Digital Light Path Labeling System with Dual Polarization Quaternary Phase-Shift Keying Modulation,
Tue Jan 08 17:24:40 EST 2013
A method and system for encoding and determining labels in a Dual Polarization (DP) Quaternary Phase Shift Keying (QPSK) signal is provided. A label frame, signature sequence, and data payload are combined using a complementary constant-weight code encoding (CCWC) encoder, the output of which is deinterleaved and differentially precoded to generate a polarized tributary of a DP-QPSK signal. This encoding can be duplicated for a second tributary of the DP-QPSK signal. The label can be determined using one or more polarizers and corresponding low-speed photodetectors, each applied to a copy of the DP-QPSK signal. The strongest output of the photodetectors is then used to determine the label. Alternatively, the DP-QPSK signal can be viewed as having XI, XQ, PH, and PV tributaries. These tributaries can then be translated into XI, XQ, YI, and YQ tributaries are encoded into a standard DP-QPSK signal.
Architecture For Reconfigurable Quantum Key Distribution Networks Based On Entangled Photons Directed By A Wavelength Selective Switch,
Tue Nov 13 16:12:20 EST 2012
A system and method for securing communications between a plurality of users communicating over an optical network. The system utilizes a fixed or tunable source optical generator to generate entangled photon pairs, distribute the photons and establish a key exchange between users. The distribution of entangled photon pairs is implemented via at least one wavelength selective switch.
Calibration Method For Interferometric Optical Signal-To-Noise RATIO Measurement,
Tue Apr 17 16:10:03 EDT 2012
Systems and methods are described that measure the OSNR of an optical channel. Embodiments provide OSNR measurement methods that distinguish the intensities of the coherent modulated signal from the incoherent noise intensity occupying the same optical band using a calibration factor .zeta..
Interferometric Optical Signal-To-Noise Ratio Measurement Using A Calibration Factor,
Tue Apr 17 16:10:01 EDT 2012
Systems and methods are described that measure the OSNR of an optical channel. Embodiments provide OSNR measurement methods that distinguish the intensities of the coherent modulated signal from the incoherent noise intensity occupying the same optical band using a calibration factor .zeta..
Method For Lightpath Monitoring In An Optical Routing Network,
Tue Oct 04 16:06:14 EDT 2011
A method and system for enabling lightpath monitoring in an optical network is disclosed. A single polarization modulator/scrambler introduces a pilot tone signal as an overlay on a plurality of optical signals on a source node and a performance monitoring unit detects the pilot tone signal to enable light path monitoring and identification through the optical network.
Digital Encoding Of Labels For Optical Packet Networks,
Tue Sep 13 16:06:08 EDT 2011
Methods and apparatuses are provided for transmitting labels in an optical packet network. Groups of K payload bits are encoded into blocks of N bits by using a code in which each of the groups of K payload bits is represented by a corresponding one of at least two distinct codewords of differing weights to form coded payload packet data, where K and N are integers and K<N. Composite packet data is produced by choosing among the at least two distinct codewords according to a value of chip data based, at least partly, on label data. An optical signal for transmission via the optical network is produced by applying the composite packet data to an optical transmitter.
Interferometric Method And Apparatus For Measuring Optical Signal Quality In Optical Communications System,
Tue Sep 13 16:06:07 EDT 2011
Differences in the interferometric patterns of modulated telecommunication signals and broadband optical noise sources are identified and are exploited in measuring the optical signal-to-noise measurements in reconfigurable photonic networks. A light output power from said interferometer corresponding to a specified delay setting in the interferometer is measured, and a coherent optical signal is distinguished from the incoherent optical noise based on the light output power measurement.
Optical Swapping Of Digitally-Encoded Optical Labels,
Tue Apr 12 16:04:50 EDT 2011
A method and a device are provided for swapping optical labels in an optical communication network. Optical information, including payload data and label data digitally encoded into the optical information, is received. At least one group of bits within the optical information is selectively inverted to rewrite the label data with new label data without changing the payload data. Each of the at least one group of inverted bits includes at least two bits and all bits of each of the at least one group of inverted bits are contiguous bits.
Optical Devices With Multiple Wafers Containing Planar Optical Waveguides,
Tue Sep 07 15:04:36 EDT 2010
A method for fabricating an optical device wherein the device comprises a first substrate wafer with at least one buried optical waveguide on an approximately flat planar surface of the substrate and a second substrate wafer with at least a second buried optical waveguide. The waveguides so formed may be straight or curved along the surface of the wafer or curved by burying the waveguide at varying depth along its length. The second wafer is turned (flipped) and bonded to the first wafer in such a manner that the waveguides, for example, may form an optical coupler or may cross over one another and be in proximate relationship along a region of each. As a result, three-dimensional optical devices are formed avoiding the convention techniques of layering on a single substrate wafer.
Interferometric Method For Measuring Optical Signal Quality In Optical Communication Systems,
Tue Mar 03 16:07:19 EST 2009
Differences in the interferometric patterns of modulated telecommunication signals and broadband optical noise sources are identified and are exploited in measuring the optical signal-to-noise measurements in reconfigurable photonic networks. A light output power from said interferometer corresponding to a specified delay setting in the interferometer is measured, and a coherent optical signal is distinguished from the incoherent optical noise based on the light output power measurement.
Optical devices with multiple wafers containing planar optical waveguides,
Tue Oct 14 18:13:02 EDT 2008
United States Patent: 7437031A method for fabricating an optical device wherein the device comprises a first substrate wafer with at least one buried optical waveguide on an approximately flat planar surface of the substrate and a second substrate wafer with at least a second buried optical waveguide. The waveguides so formed may be straight or curved along the surface of the wafer or curved by burying the waveguide at varying depth along its length. The second wafer is turned (flipped) and bonded to the first wafer in such a manner that the waveguides, for example, may form an optical coupler or may cross over one another and be in proximate relationship along a region of each. As a result, three-dimensional optical devices are formed avoiding the convention techniques of layering on a single substrate wafer.
Delivering multicast services on a wavelength division multiplexed network using a configurable four-port wavelength selective crossbar switch,
Tue Apr 29 18:12:46 EDT 2008
A method and a system in which selected wavelengths of a wavelength division multiplexed (WDM) signal are modulated with multicast data for multicasting data services on an optical network. The WDM signal is received from a hub node of the optical network, such as a unidirectional ring network or a bi-directional ring network. A four-port wavelength crossbar switch (4WCS) selectably switches selected wavelengths from the optical network to a modulator loop. The modulator loop includes a multicast modulator that modulates the selected plurality of wavelengths with the multicast data. Each modulated wavelength is then switched back to the optical network by the 4WCS switch, and sent to a plurality of subscriber nodes of the optical network. This architecture allows a facility provider to be physically separated from a content provider, and affords the flexibility of selectively delivering multicast content to individual subscribers.
Method for fabricating optical devices by assembling multiple wafers containing planar optical waveguides,
Tue Apr 22 18:12:44 EDT 2008
An optical device comprises a first substrate wafer with at least one buried optical waveguide on an approximately flat planar surface of the substrate and a second substrate wafer with at least a second buried optical waveguide. The waveguides so formed may be straight or curved along the surface of the wafer or curved by burying the waveguide at varying depth along its length. The second wafer is turned (flipped) and bonded to the first wafer in such a manner that the waveguides, for example, may form an optical coupler or may cross over one another and be in proximate relationship along a region of each. As a result, three-dimensional optical devices are formed avoiding the convention techniques of layering on a single substrate wafer.
Method for fabricating optical devices by assembling multiple wafers containing planar optical waveguides,
Tue Jan 16 18:11:49 EST 2007
A method for fabricating optical devices comprises the steps of preparing a first substrate wafer with at least one buried optical waveguide on an approximately flat planar surface of the substrate and a second substrate wafer with at least a second buried optical waveguide. The waveguides so formed may be straight or be curved along the surface of the wafer or curved by burying the waveguide at varying depth along its length. The second wafer is turned (flipped) and bonded to the first wafer in such a manner that the waveguides, for example, may form an optical coupler or may crossover one another and be in proximate relationship along a region of each. As a result, three dimensional optical devices are formed avoiding conventional techniques of layering on a single substrate wafer. Optical crossover angles may be reduced, for example, to thirty degrees from ninety degrees saving substrate real estate. Recessed areas may be provided in one or the other substrate surface reducing crosstalk in a completed three dimensional crossover device. Three dimensional optical couplers may comprise waveguides of identical or dissimilar characteristics. Moreover, three dimensional optical switches may be formed using the proposed flip and bond assembly process.
Method for fabricating optical devices by assembling multiple wafers containing planar optical waveguides,
Tue Aug 01 18:11:26 EDT 2006
A method for fabricating optical devices comprises the steps of preparing a first substrate wafer with at least one buried optical waveguide on an approximately flat planar surface of the substrate and a second substrate wafer with at least a second buried optical waveguide. The waveguides so formed may be straight or be curved along the surface of the wafer or curved by burying the waveguide at varying depth along its length. The second wafer is turned (flipped) and bonded to the first wafer in such a manner that the waveguides, for example, may form an optical coupler or may crossover one another and be in proximate relationship along a region of each. As a result, three dimensional optical devices are formed avoiding conventional techniques of layering on a single substrate wafer. Optical crossover angles may be reduced, for example, to thirty degrees from ninety degrees saving substrate real estate.
Delivering multicast services on a wavelength division multiplexed network using a configurable four-port wavelength selective crossbar switch,
Tue Apr 11 18:11:05 EDT 2006
A method and a system in which selected wavelengths of a wavelength division multiplexed (WDM) signal are modulated with multicast data for multicasting data services on an optical network. The WDM signal is received from a hub node of the optical network, such as a unidirectional ring network or a bi-directional ring network. A four-port wavelength crossbar switch (4WCS) selectably switches selected wavelengths from the optical network to a modulator loop. The modulator loop includes a multicast modulator that modulates the selected plurality of wavelengths with the multicast data. Each modulated wavelength is then switched back to the optical network by the 4WCS switch, and sent to a plurality of subscriber nodes of the optical network. This architecture allows a facility provider to be physically separated from a content provider, and affords the flexibility of selectively delivering multicast content to individual subscribers.
Four-port wavelength-selective crossbar switches (4WCS) using reciprocal WDM MUX-DEMUX and optical circulator combination,
Tue Jun 15 01:05:24 EDT 2004
A four-port wavelength-selective crossbar switch generates an add/drop wavelength signal from a wave division multiplexed (WDM) signal using a plurality of double-sided reflectors that selectively reflects a selected wavelength channel signal of the WDM signal through optical circulators to provide low crosstalk between the dropped and added wavelength signals. The switch also reduces the number of WDM MUX-DEMUX required to one half that compared to a traditional approach. Furthermore, the switch can be designed to be wavelength cyclic with individual free spectral ranges that can be independently set to either through or add/drop states.
Wavelength-Cyclic Communication Network And Wavelength-Cyclic Add/Drop Modules,
Tue Sep 02 18:08:50 EDT 2003
A method and apparatus for providing wavelength-cyclic communication services. M wavelength channels are provided to a plurality of add/drop modules in the network, and each of the add/drop modules selects a distinct comb of wavelength channels for provision to a subscriber. The add/drop modules select a comb of wavelength channels such that each selected channel is separated by N wavelength channels from adjacent selected channels. Thus, each add/drop module can select M/N channels for a corresponding subscriber. A passive Fabry-Perot interferometer having controlled dispersion can function as a wavelength selector at each add/drop module. The Fabry-Perot interferometer can have two different materials having different dispersion properties provided in an interference cavity, thereby providing desired tunability characteristics for the interferometer.
