共查询到20条相似文献,搜索用时 31 毫秒
1.
M. S. Leeson 《Optical and Quantum Electronics》2006,38(8):667-673
The implementation of wavelength division multiplexing (WDM) in communication access networks is dependent upon the availability of low cost optical sources. One possible alternative to lasers is to employ slices of a broadband optical source obtained via optical filters, which may be tuneable. This paper considers the behaviour of such a spectrally sliced optical transmission system as a function of the bandwidth of a realistic receiver electrical filter for the first time. The treatment includes distortion from optical fibre dispersion over several kilometres of fibre. The optimum ratio between the electrical bandwidth and the optical bit rate is found to be ~0.6 for a fifth-order Bessel filter 相似文献
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Edward Mutafungwa Seppo J. Halme Kamugisha Kazaura Mitsuji Matsumoto Toshihiko Wakahara 《International Journal of Infrared and Millimeter Waves》2003,24(7):1113-1126
In this paper, we propose and simulate 2 OCDM × 4 WDM transmission system for a millimeter-wave (60 GHz) over fiber system to be used in broadband wireless access networks (BWANs). The general system setup is devised and the necessary building blocks identified. Results gathered (for a 155 Mbit/s per user system) under worst case parameter specifications and settings suggest indicate that system performance is severely limited by optical multiuser interference (OMUI) penalties. Several methods to reduce the OMUI limitations are described. These methods should ensure that this transmission scheme possible wavelength-reuse option for future MMW BWANs. 相似文献
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由于WDM网络中的传输和交换是以波长为粒度进行的。因此波长分配算法就成为光网络的研究热点。有效的算法可大大提高波长的利用率,并可充分挖掘WDM的带宽资源。介绍了WDM全光网络中静态和动态波长分配算法,尤其是结合大型网孔网络详述了几种动态波长分配算法。针对波长变换器在全光网络中的应用。提出了一种可以解决任意类型光网络的分层图算法,它可以一次性解决路由选择和波长分配问题,大大提高了该算法的效率。是未来光网络中非常有前景的一种波长分配算法。 相似文献
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Tarek S. El-Bawab Chintan H. Vaishnav Anura P. Jayasumana Henryk Temkin Jon R. Sauer Heinz A. Willebrand 《Fiber and Integrated Optics》1997,16(3):237-260
The wavelength division multiplexing (WDM) network architectures, in general, are based on transmitters and/or receivers that can be precisely and speedily tuned to predetermined, fixed wavelengths. These requirements are not easy to meet in practice. Robust WDM, the subject of this paper, has been introduced as a technique to implement WDM in the local area. The strength of this novel approach is that it does not rely on wavelength-sensitive devices that are required to perform with extreme stability. This paper describes the basis of this approach and presents two types of medium access control (MAC) protocols that are suitable for Robust WDM local area networks (LANs). The performance of networks based on these protocols is discussed in detail. It is shown that the new approach has considerable promise for WDM networks in the local area. 相似文献
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A. D'Errico R. Proietti G. Contestabile E. Ciaramella 《Fiber and Integrated Optics》2013,32(4):223-228
Abstract Using differential phase shift keying, we fully exploit semiconductor optical amplifiers (SOAs) for signal amplification in practical Wavelength Division Multiplexing (WDM) Nx10 Gbit/s unrepeated systems. Record transmission experiments are presented, thus making SOAs a competitive amplification alternative in metro and extended-metro networks. 相似文献
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A fiber-based wavelength-division-multiplexing (WDM) network utilizing polarization multiplexing (PolMUX) is proposed to simultaneously provide broadband wireless and wired services. In such a dual-service access network, the wireless and wired services are separately delivered in two orthogonal states of polarization with well independence in a single WDM channel. The impact of several polarization-dependent interferences becomes insignificant due to the relatively short transmission distance in access networks. The feasibility of PolMUX is experimentally demonstrated with a power penalty at BER = 10-9 of about 0.5 dB and 1 dB for 2.5 Gb/s wired and wireless downstream services, respectively. The proposed system is compatible with the current reported techniques in either WDM passive optical networks (WDM-PON) or radio-over-fiber (ROF) systems. 相似文献
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Poladian L 《Optics letters》2001,26(1):7-9
The design of wavelength-division-multiplexed (WDM) filters requires control of both the attributes of the filter within the reflection band and the filter's effects on adjacent bands. Causality arguments are used to give the minimum dispersion that can be achieved in the transmission of an adjacent channel in terms of the bandwidth, sidelobe suppression, and channel spacing of WDM filters. The ripple in the side-channel dispersion is also related to the sidelobe properties. Results for a synthesized grating design and its calculated spectrum are compared with the theoretical limits on dispersion. 相似文献
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F. Tillerot M. J. Chawki V. Tholey D. Hui Bon Hoa H. Dupont R. Auffret 《Fiber and Integrated Optics》1996,15(4):281-289
This paper proposes the introduction of the multiwavelength technique in the three layers of a SDH-based network. In the trunk layer, wavelength division multiplexing (WDM) takes advantage of the optical parallelism in a single fiber. Cross-connection can be achieved either passively (i.e., with tunable filters) or by means of wavelength converters. The latter solution, which offers high flexibility, was implemented in a 4 × 4 optical routing element. In the junction network the feasibility of a three-station WDM self-healing ring was demonstrated. Finally, in the access network, synchronous burst access and time and wavelength division multiplexing (T/WDM) switching is proposed to offer service flexibility to the subscribers. 相似文献
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S.M. Shahruz 《Physica D: Nonlinear Phenomena》2008,237(20):2531-2538
In this paper, the regulating effect of guiding filters on the energies of solitons in wave-length division multiplexing (WDM) transmission systems is rigorously studied. More precisely, it is shown that guiding filters prevent the energies of solitons from decaying to zero in long distances. This goal is achieved by studying a mathematical model of the evolution of energies of solitons in transmission systems. The approach is mathematical and does not use numerical or experimental results available in the literature; nevertheless, it reaffirms such results. 相似文献
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Y. Su Y. Tian E. Wong N. Nadarajah C.C.K. Chan 《Laser \u0026amp; Photonics Reviews》2008,2(6):460-479
We review recent progress on all‐optical virtual‐private‐network (VPN) schemes in passive optical networks (PONs). PON is a promising candidate in future access areas to provide broadband services with low cost. With all‐optical virtual private network (VPN) function, PON can support efficient internetworking among end users with dedicated optical channels, thus enabling guaranteed bandwidth and enhanced security at the physical layer. Here, we discuss and compare existing schemes of all‐optical VPNs in time‐division‐multiplexed (TDM) PONs, and also recently proposed schemes for deployment in wavelength‐division‐multiplexed (WDM) PONs and two‐stage TDM/WDM PONs. 相似文献
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We have fabricated 9-channel silicon wavelength-division-multiplexing (WDM) ring filters using 193 nm deep-ultraviolet (DUV) lithography and investigated the spectral properties of the ring filters by comparing the transmission spectra with and without an upper cladding. The average channel-spacing of the 9-channel WDM ring filter with a polymeric upper cladding is measured about 1.86 nm with the standard deviation of the channel-spacing about 0.34 nm. The channel crosstalk is about −30 dB, and the minimal drop loss is about 2 dB. 相似文献
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Diffraction of light by acoustic waves that are generated in the acoustooptic cells of piezoelectric transducers with complex geometry is studied. The diffraction by acoustic beams with triangular, quadrangular (rhombic), hexagonal, etc., cross sections, when the lengths of light-sound interaction in the cross-sectional area of the light beam are different, is considered in the plane wave approximation. The difference in the length of interaction affects the instrument function of acoustooptic devices and provides the suppression of the side lobes in their transmission function. The advantages of using cells with complex-geometry transducers in tunable acoustooptic filters that are incorporated into fiber-optic communication lines with wavelength-division multiplexing (WDM) are discussed. 相似文献
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We describe an architecture design and implementation of the optically transparent wavelength-division-multiplexed (WDM) asynchronous-transfer-mode (ATM) multicast (3M) switch for all optical high-speed networks. By using the WDM techniques, the wire complexity in both the switch fabric and the concentrator can be reduced from O(N2) to O(N). By using integrated photonic devices and highly parallel processing and pipeline control electronic circuits the switch is handling signals at the cell level (53 bytes) instead of at the bit level and can achieve very high speed and high throughput operation. Several key components, including a cell synchronizer, a photonic VCI over-writting unit, a wavelength converter, an optical concentrator, and a WDM memory, have also been proposed to realize this 3M switch. All of the photonic devices are highly integratable and are very suitable for building future large-scale, low-cost photonic ATM switches. A combination of both the ATM and WDM techniques will provide an ultimate version for optical networking with almost unlimited capacity. 相似文献
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波分复用薄膜带通滤光片的中心波长温度稳定性 总被引:8,自引:3,他引:5
讨论了影响波分复用薄膜滤光片中心波长漂移的因素 ,着重分析了滤光片的温度稳定性。根据实验结果 ,借助于高桥模型 ,分析计算了滤光片的折射率温度系数、线膨胀系数和泊松比以及它们对温度漂移的影响。得到了Ta2 O5/SiO2 滤光片薄膜的折射率温度系数、线膨胀系数、泊松比分别为 1× 10 -5℃-1,5× 10 -7℃-1和 0 12 ,指出了这三个参量是影响温度稳定性最重要的因素 ,特别是薄膜的折射率温度系数。对特定的基板热膨胀系数 ,通过调节滤光片的干涉级次和间隔层材料 ,可望得到零温度漂移的稳定滤光片。 相似文献
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Hai-Han Lu Hsien-Li Ma Yao-Wei Chuang Yu-Chieh Chi Che-Wei Liao Hsiang-Chun Peng 《Optics Communications》2007,270(2):211-216
We proposed and demonstrated a bidirectional wavelength-division-multiplexing (WDM)–passive optical network (PON) employing injection-locked Fabry–Perot laser diodes (FP LDs) at both transmitting sites, and adaptive filters at both receiving sites. Injection-locked FP LDs, a particularly inexpensive option, are used to replace the conventional distributed feedback (DFB) LDs in WDM–PON. Adaptive filters are attractive because they can track the variations and compensate the nonlinear distortions. Transmission performance over 20 km of a standard single-mode fiber (SMF) was investigated. Improved performance of bit error rate (BER), better and clear eye diagram were achieved in our proposed WDM–PON. 相似文献