Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J

Publications in this journal

• Article: Performance limit of fibre-optic gas sensors from coherent backscatter

  Jin W, Demokan M.S, Stewart G, Philp W, Culshaw B
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1998; 145(3):186-190.
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  Available from: inescporto.pt

  Article: Performance assessment of FM broadcast subcarrier-multiplexed optical systems

  H.M. Salgado, J.J. O'Reilly
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  ABSTRACT: The performance of frequency-modulated (FM) subcarrier-multiplexed systems is assessed using Volterra series analysis to model laser nonlinear distortion accurately. The intermodulation-power spectral density and the carrier-to-intermodulation ratio are then determined. The performance of these systems is investigated by considering all noise contributions: intermodulation and relative intensity noise in the transmitter,and receiver thermal and shot noise. Optimum performance is also identified. A 62-channel FM video system occupying the bandwidth of 2.7-5.2 GHz provides an illustrative example
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1994;
• Article: RACE R2005: microwave optical duplex antenna link

  J.J. O'Reilly, P.M. Lane, M.H. Capstick, H.M. Salgado, R. Heidemann, R. Hofstetter, H. Schmuck
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  ABSTRACT: The paper describes the results to date of the RACE project R2005. The project addresses the optical generation and fibre delivery of mm-wave signals for future mobile radio and remote customer access connections. The authors identify potential application areas and appropriate performance targets for such fibre/mm-wave systems. The major issue identified is the need to achieve low-cost antenna units due to the large number of such units that would be required; this arises from the limited propagation distances achievable at mm-wave frequencies. A brief review of current optical methods for the generation of mm-waves allows the identification of the inadequacies of these techniques and leads to a description of a new method, developed for the project, that overcomes most of the disadvantages outlined earlier
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1994;
• Article: Analogue intensity modulation schemes for optical fibre HDTV transmission

  J.M. Senior, D.T. Lambert, D.W. Faulkner
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  ABSTRACT: The major analogue intensity modulation schemes are assessed and compared in relation to their ability to provide high-quality transmission of high-definition television (HDTV) signals on single-mode optical fibre. The practical investigation and novel implementations for subcarrier frequency modulation (SCFM) and square wave frequency modulation (SWFM) schemes are then described prior to discussion of the relative performance attributes of these transmission systems. Both modulation techniques proved satisfactory for high-quality HDTV transmission over single-mode fibre with the balance of the measured performance and the necessary system requirements not decisively favouring either method
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1994;
• Article: Pulse time modulation techniques for optical communications: a review

  B. Wilson, Z. Ghassemlooy
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  ABSTRACT: The principal factor in realising a high-performance bandwidth-efficient fibre communication system at an acceptable cost is the choice of modulation format on the optical carrier. In this context, pulse time modulation (PTM) techniques represent an attractive alternative to purely digital or analogue methods. The PTM family is reviewed, a classification system is proposed and their potential for use in high-speed fibre systems intended for the transmission of analogue data is examined
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1994;
• Article: Design and optimisation of a fully integrated GaAs tuned receiver preamplifier MMIC for optical SCM applications

  P.M.R.S. Moreira, I.Z. Darwazeh, J.J. O'Reilly
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  ABSTRACT: A tuned SCM optical receiver design integrated as a GaAs MMIC is reported. The receiver is intended for use in a practical system and includes an integrated noise tuning network. A critical study of tuning networks suitable for integration is undertaken, and the details of a novel design and optimisation strategy for such networks are discussed. Simulation results predict low noise and high gain performance, and verify the validity of the design technique adopted
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1994;
• Article: Method for block synchronisation in optical PPM

  H. Sugiyama
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  ABSTRACT: A method for block synchronisation in optical PPM is proposed. This method is an application of the synchronisation method for PN sequences normally used in spread spectrum communication systems. In this method, the phase of the synch signal is shifted little by little, with the synch decision process carried out on the receiving side until synchronisation is attained. The decision rule is based on the fact that the number of received pulses in each frame of the synch signal must be one and that the time when the pulse is received should not be in the pre-fixed prohibited frame slot, provided that synchronisation is established. This method's synchronisation characteristics are investigated, and it is shown that block synchronisation can be established sufficiently with only 12.5% of additional prohibited slots
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1994;
• Article: Optimal and suboptimal detection of optical fibre digital PPM

  R.A. Cryan, R.T. Unwin
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  ABSTRACT: The discrete time modulation format, known as digital PPM, has been used to exchange channel bandwidth for improved signal-to-noise ratio in optical communication systems. However, the filter that optimises signal detection is complex in that it comprises a prewhitened matched filter in cascade with a proportional-derivative-delay network. In this form, the receiver would be unrealistic for a commercial system. This paper examines the use of both optimum and suboptimum detection. Three suboptimum predetection filters are considered: a matched filter, an optimised three-pole filter and a third-order Butterworth filter. Original receiver sensitivity calculations, carried out at a bit rate of 140 Mbit/s and a wavelength of 1.3 pm, show that the optimum digital PPM system offers an 8.6 dB improvement over a typical PCM system. The suboptimum predetection filters result in sensitivity degradations of 0.4, 0.9 and 1.1 dB, respectively. This clearly illustrates that receiver complexity can be simplified without large reductions in sensitivity. In particular, the well known and simple Butterworth filter can be employed with only 1.1 dB degradation in sensitivity
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1994;
• Article: Use of optical amplifiers to increase distribution capacity of optical analogue video systems

  M.J. Pettitt
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  ABSTRACT: Optical amplifiers can be used to increase the distribution of analogue video signals over a passive optical network. The paper analyses the gains in system loss budget that can be obtained from the positioning of optical amplifiers either as transmitter power amplifiers, line amplifiers or receiver preamplifiers in a distribution network. Both AM and FM subcarrier multiplexed (SCM) video systems are considered within the constraints of operating with safe optical power levels on optical lines in the network. It is shown that under such conditions optical amplifiers can give significant advantages in the loss budget for FM SCM systems, but have limited application within AM SCM systems
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1994;
• Article: Soliton pulse-position modulation

  J.M. Arnold
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  ABSTRACT: The dynamical behaviour of infinite periodic trains of optical fibre solitons subjected to modulation of the position of each soliton is studied by analytical methods. It is concluded that multigigahertz pulse-analogue transmission over amplified links many times longer than the linear dispersion limit at high signal-to-noise ratio is achievable. The principal limitations are the nonlinear intersoliton interaction and amplifier spontaneous emission. The analytical techniques developed are useful for the study of a wide range of modulation and noise phenomena in soliton pulse trains
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1994;
• Article: Effect of laser diode characteristics on the performance of an SCM-OFDM direct detection system

  L. Chao
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  ABSTRACT: This paper describes: the application of the microwave subcarrier multiplexing technique (SCM) in an optical frequency division multiplexing (OFDM) system which employs an optical FM direct detection scheme. Direct frequency modulation of a laser diode offers the advantages of compact optical spectrum and simple driving circuit; it also permits a more effective utilisation of optical channel capacity. The carrier-to-noise ratio performance of each subcarrier channel is evaluated. The effect of laser diode phase noise and relative intensity noise as well as the intermodulation product of subcarrier channels on the overall system performance is analysed and the results presented
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 01/1994;
• Article: Novel approaches to polarisation-independent switches

  P. Granestrand
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  ABSTRACT: Two new contributions on the subject of polarisation-independent switches are presented. The first concerns experimental results on a polarisation-independent directional coupler with extremely relaxed fabrication tolerances, and the second is a proposal for a digital optical switch in unconventional orientation
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 11/1993;
• Source

  Available from: unipi.it

  Article: Architecture for large dilated optical TDM switching networks

  D.K. Hunter, P.J. Legg, I. Andonovic
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  ABSTRACT: A novel architecture for optical TDM switching is introduced, comprising 2×2 optical switches integrated onto large substrates, and fibre delay lines. The performance of the architecture is characterised in terms of switch count, crosstalk, frame delay, attenuation and control complexity. It is shown that in the near future a system with 16 inputs and outputs, handling a total of 4096 TDM channels, could be demonstrated experimentally with 448 switches on six substrates using state-of-the-art-technology,
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 11/1993;
• Article: InP digital optical switch: key element for guided-wave photonic switching

  J.-F. Vinchant, M. Renaud, M. Erman, J.L. Peyre, P. Jarry, P. Pagnod-Rossiaux
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  ABSTRACT: The InP digital optical switch presented is compared with other types of switch. In addition to reverse- and forward-bias operation, its push-pull mode of operation is demonstrated for the first time, as well as its high-speed behaviour. The high potential of the digital optical switch and switching matrix fabrication are described. The results show that the InP-based digital optical switch has to be considered as a key element for guided-wave photonic switching
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 11/1993;
• Article: Properties of optical switching networks with passive or active space switches

  L. Gillner
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  ABSTRACT: Fibre optical communications switching networks with optical nodes containing optically passive (lithium niobate) or active (indium phosphide) space switches as well as erbium-doped fibre amplifiers are analysed numerically from a power budget point of view. Calculations include spectral gain characteristics and gain saturation in the optical amplifiers caused by accumulated amplified spontaneous emission and optical signals. Active switches require less transmitter optical power than the passive switches for passage through a given number of nodes because of their lower losses. Critical parameters are identified as the loss in the optical node and the saturation output power of the optical amplifiers
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 11/1993;
• Article: All-optical clock extraction using two-contact devices

  P. Barnsley
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  ABSTRACT: A comprehensive summary of the operation of two-contact semiconductor self-pulsating laser diode (SP-LD) in both return-to-zero (RZ) and non-return-to-zero (NRZ) optical transmission systems is presented. Results demonstrate that this type of device has great potential as the basis for all-optical clock recovery circuits at multi-Gbits rates for switching applications. Results describe the basic device behaviour showing how zinc doping the shorter (absorber) of the device enables repeatable and controlled GHz pulsations, within the range ~0.6 GHz and tunability (via the DC gain current) over many GHz, to be achieved. Experimental results show that the SP-LD can be locked with μW of incident power to produce a locked oscillator with a linewidth of <10 Hz at 5 GHz and with 20 dB power gain across the device. New results, addressing the pattern dependence, demonstrate that long breaks (up to ~30 `zeros') in the clock can be accommodated without significant degradation of the locked clock purity; the length of break being dependent on the initial state of locking. Other new results show that time for such circuits is of the order of 100 clock cycles. System performance is investigated using these devices within a 20 Gbit/s (4×5 Gbit/s) optical-time-division-multiplexed demonstrator; the results showing no significant degradation of the bit-error-ratio performance. Other system results at 3.2 Gbit/s show that this technique can be applied to NRZ systems when also utilising a nonlinear effect within a similar device biased below threshold, and identifying the differences from RZ operation. These results show that such an approach could provide major benefits in developing the next generation of telecommunications networks
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 11/1993;
• Article: Optical switching in the twin-guide travelling-wave laser amplifier

  D.M. Atkin, M.J. Adams
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  ABSTRACT: Detailed calculations have been made of the optical switching behaviour in twin-guide travelling-wave laser amplifiers driven with equal current in each guide. For typical device parameters, appropriate to 1.55 μm InGaAsP devices, the analysis indicates that the switching occurs at about one quarter of the saturated power, which in practice means at about 1 mW for an unsaturated gain of 26 dB. The factors influencing this switching power are discussed and some suggestions offered as to ways of reducing the value
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 11/1993;
• Article: Spectral characteristics of coupled-waveguide Bragg-reflection tunable optical filter

  J.-P. Weber
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  ABSTRACT: The transmission and reflection spectrum of the coupled-waveguide Bragg-reflection filter are computed by a new method. The filter is based on the use of a Bragg grating to obtain contradirectional coupling between two dissimilar waveguides. The analysis shows that the tuning range should be similar to that of a simple Bragg grating filter, but with the advantage of having the output separated from the input. This device could also be used as a selective tap in a wavelength-division multiplexing system
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 11/1993;
• Source

  Available from: unipr.it

  Article: Soliton ultrafast all-optical mesh networks

  A. Bononi, F. Forghieri, P.R. Prucnal
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  ABSTRACT: Channel transmission error arguments show how the size of an all-optical multihop network employing deflection routing is limited for a given optical bit rate. These limits are quantified for nonregenerative all-optical mesh networks such as Manhattan Street network and ShuffleNet employing solitons. It is found that the node-to-node fibre span cannot exceed a few kilometres for network sizes up to 400 nodes when the optical bit rate is as high as 100 Gbit/s if the packet error rate is to be bounded below 10^-6
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 11/1993;
• Article: Carrier-induced MESFET optical switches for photonic integration

  D.K. Gautam, K. Ishida
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  ABSTRACT: A study is made of the reverse-biased optical switches in a MESFET geometry. Carriers are controlled in the switching region by the gate voltage which can enhance the feasibility of carrier-induced devices in high-speed data communication, optical computing and photonic switching. A waveguide optical switch in a conventional MESFET geometry is proposed which gives an extinction ratio better than 8.75 dB at the operating voltage of 7 V. A further optimised structure to reduce the operating voltage and get better optical characteristics has been designed. Computer analysis of the two-dimensional electrostatic potential and the number of depleted carriers shows that diffused carriers are depleted by applying drain and gate voltages of 2 and -2 V, respectively. The beam propagation method applied to wave propagation shows an on/off ratio better than 15 dB. This considerably improves both electrical and optical characteristics of carrier injection-type optical switches
  Optoelectronics [see also IEE Proceedings-Optoelectronics], IEE Proceedings J 11/1993;