共查询到20条相似文献,搜索用时 15 毫秒
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T. Honda A.C. Liu J. Valera J. Colvin K. Sawyer R.R. McLeod 《Photonics Technology Letters, IEEE》2003,15(1):69-71
A novel wavelength-division-multiplexing add-drop module is proposed using free-space cascaded thin-film filters. The athermal design of the filters creates a natural curvature that is shown to compensate for diffraction and optical misalignment. We demonstrate an insertion loss of 1.1 dB for four cascaded filters. 相似文献
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The simultaneous generation of 60 discrete wavelengths, with a 75 GHz interwavelength spacing, from a modelocked semiconductor diode laser is reported. The individual wavelengths are emitted as mutually synchronised 898 MHz return-to-zero pulse trains. Optical spectra and temporal diagnostics are provided 相似文献
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Turkiewicz J.P. Tangdiongga E. Rohde H. Schairer W. Lehmann G. Khoe G.D. de Waardt H. 《Electronics letters》2003,39(10):795-796
The authors describe the excellent capability of an all-optical gain-transparent ultrafast nonlinear interferometer (GT-UNI) in dropping, passing through, and adding optical time domain multiplexing (OTDM) channels. Error free operation without significant penalties of a complete OTDM add-drop node at 80 Gbit/s was achieved. 相似文献
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The performance of resonant channel-dropping filters in wavelength-division multiplexing (WDM) applications is computed. 31 and 50 filters are cascaded along a single bus with crosstalks of -27 and -14 dB, respectively. The temporal response of the filter for a secant-hyperbolic pulse stream at 400 Mb/s and 1 Gb/s is presented. The simulation shows the promise of resonant-filter cascades.<> 相似文献
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Glance B. Doerr C.R. Kaminow I.P. Montagne R. 《Lightwave Technology, Journal of》1996,14(11):2453-2456
An optically restorable wavelength division multiplexing (WDM) ring network carrying ATM traffic is presented. It uses a new architecture with simple add/drop circuitry allowing traffic restoration in case of a ring breakage by independent local actions at the affected nodes. Multisession video traffic at 155 Mb/s was demonstrated between stations distributed along the ring. No visible video degradation was observed during the 50 ms restoration time caused by a ring breakage 相似文献
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Wavelength channel data rewrite using saturated SOA modulator for WDM networks with centralized light sources 总被引:1,自引:0,他引:1
This paper describes a method for realizing the efficient utilization of wavelength resources in wavelength-division multiplexing networks with centralized light sources. Using a deeply saturated semiconductor optical amplifier (SOA) modulator located in a remote node (RN), we erase the data on a downstream signal with a low extinction ratio and modulate it with new data to generate an upstream signal. Thus, we use only one wavelength for bidirectional transmission between a center node and an RN, without placing lasers at the RN. In this paper, we analyze the data suppression characteristic of the SOA using a large signal model. We also estimate the bit error rate degradation in the presence of an unsuppressed downstream bit pattern in an upstream signal. We then report experimental results that confirm the basic characteristics of the wavelength channel data rewriter, which we constructed using a linear amplifier and an SOA. Finally, we provide the results of a data transmission experiment that we undertook using the data rewriter. 相似文献
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Traditional ROADM networks strictly follow the coarse ITU-T standard wavelength grids and channel spacings, which would result in low optical spectrum utilizations under dynamic traffic requests of variable spectrum lightpaths. This paper presents a spectrum-efficient optical drop-add-drop network with a centralized multi-carrier light source (C-MCLS). The C-MCLS generates thousands of optical carriers with uniform and narrow channel spacings. The optical carriers are distributed to each network node as light sources on demand through ROADMs designed with the carrier-drop function. Spectrum-aware optical carrier allocation is studied first in the proposed network. This paper proposes a Minimum Fragmentation Request First (MinFragRF) optical carrier allocation algorithm compared with the Maximum Spectrum Request First (MaxSRF) and Minimum Spectrum Request First (MinSRF) allocation algorithms. This paper also studies how channel spacings of optical carriers impact on the network performance under variable traffic demands. We perform both network analysis and simulations to evaluate the network performance in terms of the lightpath blocking probability (LP_BP) and the effective spectrum efficiency. We analytically derive the formulas of LP_BP and average effective spectrum efficiency in the proposed network. Simulation results show that the proposed network with more narrow channel spacings greatly reduces the lightpath blocking probability compared with the traditional ROADM network. The average effective spectrum efficiency of the proposed network can be improved about 100 % compared with that of the traditional ROADM network by choosing appropriate network design parameters. The MinFragRF allocation algorithm has a better LP_BP performance than that of the MaxSRF and has a better spectrum utilization efficiency than that of the MinSRF. The optimal channel spacing evaluations show that narrow channel spacings such as 6.25 and 12.5 GHz greatly improve LP_BP performance when low bit-rate traffic requests dominate in the traffic model. However, as the high bit-rate traffic requests increase, the performance advantage of narrow channel spacings is gradually disappearing. 相似文献
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Optical performance monitoring (OPM) is an important approach to determine the quality of optical channels within an optical core network without passing data through optoelectronic regeneration at the monitor points. Using this approach, the quality or “health” of signals can be determined at arbitrary points in a network without knowledge of the transport history of the data or the details of the transmission path. We report experimental results on the use of subcarrier multiplexing (SCM) to perform a variety of monitoring functions including chromatic dispersion monitoring, wavelength registration, power monitoring, and signal-to-noise ratio (SNR) monitoring 相似文献
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Tunable multiwavelength fiber ring lasers using a programmable high-birefringence fiber loop mirror 总被引:3,自引:0,他引:3
L.R. Chen 《Photonics Technology Letters, IEEE》2004,16(2):410-412
We demonstrate a comb filter with digitally tunable wavelength spacing using a programmable high-birefringence (HiBi) fiber loop mirror (FLM). We then use the HiBi-FLM to implement a tunable multiwavelength semiconductor optical amplifier (SOA)-based fiber ring laser and a tunable multiwavelength all-fiber Raman ring laser. Both lasers exhibit stable room-temperature operation and have a wavelength spacing that is digitally tunable between 1.6 and 3.2 nm. With the SOA-based configuration, we obtain six wavelengths with a spacing of 3.2 nm and 11 wavelengths with a spacing of 1.6 nm; with the all-fiber Raman-based configuration, we obtain four wavelengths with a spacing of 3.2 nm and five wavelengths with a spacing of 1.6 nm. 相似文献
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Hybrid WDM/TDM PON using the AWG FSR and featuring centralized light generation and dynamic bandwidth allocation 总被引:2,自引:0,他引:2
A novel time/space/wavelength division multiplexing (TDM/WDM) architecture using the free spectral range (FSR) periodicity of the arrayed waveguide grating (AWG) is presented. A shared tunable laser and a photoreceiver stack featuring dynamic bandwidth allocation (DBA) and remote modulation are used for transmission and reception. Transmission tests show correct operation at 2.5 Gb/s to a 30-km reach, and network performance calculations using queue modeling demonstrate that a high-bandwidth-demanding application could be deployed on this network. 相似文献
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Sang-Wan Ryu Sung-Bock Kim Jae-Sik Sim Jeha Kim 《Photonics Technology Letters, IEEE》2002,14(12):1656-1658
We propose a multiwavelength laser array associated with asymmetric sampled grating lasers. The laser was designed to operate at the first-order reflection of a sampled grating with the aid of an index shifter. A four-channel laser array with 400-GHz wavelength spacing was fabricated and its operation at designed wavelengths was confirmed. Individual lasers showed a threshold current of 11-17 mA and slope efficiency of around 0.18 W/A. A high side-mode suppression ratio over 39 dB was observed as well. 相似文献
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Yueping Cai Motoharu Matsuura Eiji Oki Naoto Kishi Tetsuya Miki 《Photonic Network Communications》2010,20(3):293-302
This article presents a resilient star-ring optical broadcast-and-select network with a centralized multi-carrier light source
(C-MCLS). It consists of a star part network and a ring part network. Optical carriers generated by the C-MCLS are broadcast
to all network nodes, which select and utilize them for data transmission. Optical carrier distribution as well as data transmission
and receiving are performed in the star part network. The ring part network is for fiber failure recovery. The network resilience
property enables the design of a fast distributed failure recovery scheme to deal with single and multiple fiber failures.
We introduce a fiber connection automatic protection switching (FC-APS) architecture that only consists of optical couplers
and 1 × 2 optical switches for each network node. Based on the FC-APS architecture, we design a distributed failure recovery
scheme to recover the carriers and data affected by fiber failures. The fiber failure detection and failure recovery operations
are performed by each network node independently only using its local information. We evaluate the recovery time of the distributed
failure recovery scheme compared with that of the centralized one. Numerical results show that the distributed scheme greatly
reduces the recovery time compared to the centralized configuration in the recoveries of both single and multiple fiber failures.
Optical power loss analysis and compensation of the recovery routes in the distributed scheme are also presented. We show
the required number of optical amplifiers for the longest recovery route in the distributed scheme under different numbers
of network nodes and fiber span lengths. 相似文献
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LOCAL AREA NETWORKS are currently enjoying tremendous popularity as a means for providing wideband interconnection and communications among data terminals, host computers and other types of digital equipment located throughout a single building or a campus of buildings. Such networks are typically based on bus, ring, or star architectures, each of which manifests its own set of advantages and disadvantages. In this paper, an architectural approach is described that draws upon and integrates the advantages found separately in these three different architectures, while avoiding the major disadvantages found in any one. This new architecture employs a centrally located short bus that provides an extremely efficient packet-switching service to the devices attached to the network. Bandwidth on the short bus is dynamically allocated in response to instantaneous demands by means of a highly efficient but flexible prioritybased bus contention scheme. The approach permits multiple priority classes with fair allocation of bandwidth within each class, along with a capability for integrated circuit and packet switching. The architecture can also make use of existing twisted-pair building wiring, and at the same time take advantage of emerging optical-fiber technology. In addition, the architecture provides a means to expand the network beyond a local area, resulting in a wide-area network capability. 相似文献
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The system issues and network applications of acoustooptic tunable filters (AOTFs) are discussed. AOTFs are thought to be attractive system components in dense wavelength-division multiplexed (WDM) networks because of their broad continuous electronic wavelength tunability and narrow filter bandwidth. Their unique multiwavelength filtering capability adds a greater dimension of flexibility to network design. The characteristics of the AOTF are reviewed from a system viewpoint and the performance and capabilities of bulk-devices, integrated-optic devices, and fiber-based devices are discussed and compared. Three network applications using the acoustooptic tunable filters are described. The first application is as wavelength-tunable receivers or taps for local users in a subscriber loop distribution network. The second is as multiwavelength tunable receivers in a broadcast local-area cross-connect for packet communication with very-high-throughput data rate. The third is as wavelength-selective space-division switch fabric for routing and cross-connect between central offices. Future prospects and various issues for future research are also discussed 相似文献
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Tholey V. Chawki M.J. Berthou L. Le Gac I. Gay E. Poudoulec A. 《Electronics letters》1994,30(16):1323-1324
An experimental optical WDM reconfigurable ring network is proposed. It is composed of three nodes incorporating tunable channel dropping receivers (TCDRs) and EDFAs. The reconfiguration and the protection of the ring are computer-controlled. The authors present first experimental results of a fully connected testbed demonstrator 相似文献
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In this paper,theoretical analysis of two-dimensional photonic crystal ring resonator(2D PCRR) based add-drop filter(ADF) is presented for coarse wavelength division multiplexing(CWDM) system to drop a channel at 1511 nm using hexagonal rods that are positioned in the square lattice.The 2D finite difference time domain(2D FDTD) method and plane wave expansion(PWE) method are used for obtaining the filter response and band structure of the filter respectively.Close to 100 dropping and coupling efficiencies at 1511 nm and 16 nm of bandwidth are observed through simulation.This is very well meeting the requirement of ITU-T G.694.2 standard,which is specified for metro access and short haul optical networks.The overall size of the proposed filter is 11.4 μm×11.4 μm.It can also be used in integrated optics. 相似文献
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Matthias an der Heiden Michel Sortais Michael Scheutzow Martin Maier 《Optical Switching and Networking》2012,9(1):61-80
Packet-switching WDM ring networks with a hotspot transporting unicast, multicast, and broadcast traffic are important components of high-speed metropolitan area networks. For an arbitrary multicast fanout traffic model with uniform, hotspot destination, and hotspot source packet traffic, we analyze the maximum achievable long-run average packet throughput, which we refer to as multicast capacity, of bi-directional shortest path routed WDM rings. We identify three segments that can experience the maximum utilization, and thus, limit the multicast capacity. We characterize the segment utilization probabilities through bounds and approximations, which we verify through simulations. We discover that shortest path routing can lead to utilization probabilities above one half for moderate to large portions of hotspot source multi- and broadcast traffic, and consequently multicast capacities of less than two simultaneous packet transmissions. We outline a one-copy routing strategy that guarantees a multicast capacity of at least two simultaneous packet transmissions for arbitrary hotspot source traffic. 相似文献