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Online ISSN 1350-911X Print ISSN 0013-5194

Electronics Letters

Volume 27, Issue 10, 9 May 1991

Volumes & issues:

Volume 27, Issue 10

9 May 1991

Demonstration of photonic fast packet switching at 700 Mbit/s data rate
Full integration of extremely large time constants in CMOS
High temperature operation of λ = 1.5 μm tensile strained multiple quantum well sipbh lasers
  • Author(s): P.J.A. Thijs ; J.J.M. Binsma ; E.W.A. Young ; M.E.W. van Gils
  • Source: Electronics Letters, Volume 27, Issue 10, p. 791 –793
  • DOI:  10.1049/el:19910496
  • Type: Article
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  • p. 791 –793 (3)
    The high temperature operation of 1.5 μm wavelength, strained-layer multiple quantum well, semi-insulating planar buried heterostructure lasers is reported. The lasers, which are grown by low-pressure organometallic vapour phase epitaxy and which have four 1.6% tensile strained In0.3Ga0.7As wells (thickness 8 nm), operate in CW mode up to heatsink temperatures of 140°C. The CW output power at 100°C is 26 mW per facet. These results are a marked improvement when compared to data reported thus far for 1.5 μm wavelength lasers.
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Ultralow dark current GaAlAs/GaAs msm photodetector
  • Author(s): A. Aboudou ; J.P. Vilcot ; D. Decoster ; A. Chenoufi ; E. Delhaye ; P. Boissenot ; C. Varin ; F. Deschamps ; I. Lecuru
  • Source: Electronics Letters, Volume 27, Issue 10, p. 793 –795
  • DOI:  10.1049/el:19910497
  • Type: Article
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  • p. 793 –795 (3)
    An interdigitated GaAIAs/GaAs metal-semiconductor-metal photodetector designed to be fully integrable with HIGFET-based digital integrated circuits and which exhibits a dark current as low as 100 pA at 10 V bias voltage is presented. Static and dynamic responsivities are reported, as well as noise properties. Photocurrents (for bias voltage higher than 4 V) comparable to those measured with a pin photodiode, and a shot noise cutoff frequency in excess of 13 GHz were recorded.
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Error rate prediction for PSK and QAM when affected by terrain multipath
Characteristics of laser-diode modules using thermally-diffused expanded core fibres
Experimental characterisation of diffuse multipath at 10.2 GHz using method of multiple windows
Perfect auto-associators Using RAM type nodes
Stabilisation of closed loop systems by time delays
Cross-phase modulation in semiconductor optical amplifier
Recursive state estimation for linear dynamic systems under algebraic constraints
Finding optimal module orientations in macrocell placement
  • Author(s): J.-C. Jeong  and  C.-M. Kyung
  • Source: Electronics Letters, Volume 27, Issue 10, p. 804 –805
  • DOI:  10.1049/el:19910505
  • Type: Article
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  • p. 804 –805 (2)
    An ILP (integer linear programming) formulation for finding the optimal module orientations in macrocell placement is reported. Compared to earlier approaches which work only for two-terminal nets based on the Euclidean metric for wire length estimation, the proposed method handles multi-terminal nets based on the Manhattan metric of the minimum bounding box of the pin positions which is more accurate. Experimental results of Benchmark examples have shown 7 to 11% reductions of half-perimeter cost wiring length.
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Application of OSRC operator of third order to electromagnetic scattering from conducting or dielectric cylinder
Room-temperature CW operation of λ = 1.55 μm InGaAsP/InP ITG-DFB-BCRW lasers with contacted surface grating
Design and fabrication of monolithically integrated DFB laser-wavelength duplexer transceivers for TPON/BPON access links
Three-guide directional coupler as polarisation independent optical switch
Transmission and saturation performance of dispersion-shifted distributed erbium fibre
  • Author(s): D.L. Williams ; S.T. Davey ; D.M. Spirit ; G.R. Walker ; B.L. Ainslie
  • Source: Electronics Letters, Volume 27, Issue 10, p. 812 –813
  • DOI:  10.1049/el:19910510
  • Type: Article
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  • p. 812 –813 (2)
    The gain spectra for a bidirectionally pumped 30 km length of lightly doped dispersion shifted erbium fibre and the amplification performance in saturation of a 54 km length of similar fibre are presented. The longer length comprised six spliced fibres with an average erbium concentration in the core of ∼60ppb and could be rendered lossless with 2 × 30 mW of pump power for low power signals. With 2 × 55 mW of pump power a peak fibre gain of 17dB at 1536nm was realised; as the input signal power was increased the gain was suppressed but the fibre remained transparent for signal powers up to –2 dBm.
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New uniplanar balun
Measurement of surface resistance of high-Tc superconductor by use of dielectric resonator
Semi-insulating layers in InP obtained by Co or Fe ion implantation
Current-mode cyclic ADC for low power and high speed applications
Capacity of cordless telephone systems with discontinuous transmission
Search for intrinsic three-phase resonator
  • Author(s): B.Z. Kaplan ; B.Z. Rabinovici ; D. Yardeni
  • Source: Electronics Letters, Volume 27, Issue 10, p. 822 –824
  • DOI:  10.1049/el:19910516
  • Type: Article
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  • p. 822 –824 (3)
    A new device entitled a three-phase resonator is suggested and developed. Because electromagnetic energies appear in pairs, the initially suggested system is strictly speaking of sixth order and consists of six reactors, three capacitors and three inductors. As a result of this relative involvement, the two symmetrically balanced three-phase modes which appear in the system oscillations interfere with one another and are masked by other modes. The desired balanced three-phase modes, which appear in the system oscillations, are emphasised and extracted by adding relatively simple means to the initially passive system of reactances. The successfully desired operation is demonstrated by simulating the device equations on a digital computer.
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Neural net nonlinear prediction for speech data
  • Author(s): R.M. Dillon  and  C.N. Manikopoulos
  • Source: Electronics Letters, Volume 27, Issue 10, p. 824 –826
  • DOI:  10.1049/el:19910517
  • Type: Article
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  • p. 824 –826 (3)
    A new, nonlinear, neural network based, predictor has been devised for the encoding of speech data. It may be used in the design of a differential pulse code modulation (DPCM) coder for speech. A hybrid neural network architecture has been employed which combines the perceptron and backpropagation paradigms, thus called the PB-hybrid (PBH). Only two neurons are needed in the backpropagation section, keeping the required overhead modest. This predictor is designed by supervised training, based on a typical sequence of digitised values of samples in a speech frame. Simulation experiments have been carried out using 15 ms frames of 16 kHz speech data. The results obtained for the prediction gain show a 3dB advantage of the PBH network over the linear predictor.
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Median and mean filters produce similar shifts on curved boundaries
  • Author(s): E.R. Davies
  • Source: Electronics Letters, Volume 27, Issue 10, p. 826 –828
  • DOI:  10.1049/el:19910518
  • Type: Article
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  • p. 826 –828 (3)
    This Letter considers the shifts produced by median filters on curved boundaries and contours, and shows that mean and Gaussian filters produce similar but generally slightly smaller shifts, the cases of linear intensity variations and of step edges being somewhat different and at opposite extremes of a continuum. In all cases, the shifts are zero for straight edges and contours, and are proportional to the angle turned through within the filter neighbourhood.
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Fabrication of periodically reversed domain structure for SHG in LiNbO3, by direct electron beam lithography at room temperature
Ultrafast pipelined adders using RTTs
  • Author(s): S. Mohan ; P. Mazumder ; R.K. Mains ; J.P. Sun ; G.I. Haddad
  • Source: Electronics Letters, Volume 27, Issue 10, p. 830 –831
  • DOI:  10.1049/el:19910520
  • Type: Article
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  • p. 830 –831 (2)
    Ultrafast adders that perform 32 bit additions in less than 1 ns using resonant tunnelling transistors (RTTs) are proposed. Simulation results showing their subnanosecond performance are presented. The adders are shown to be better than others in terms of both area and speed. These results are obtained using true bistable logic which makes use of the bistability of circuits using the negative differential resistance (NDR) characteristic of the RTTs.
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Filter characteristics of DBR amplifier with index and gain coupling
Using cold FET to check accuracy of microwave noise parameter test set
  • Author(s): L. Escotte ; R. Plana ; J. Rayssac ; O. Llopis ; J. Graffeuil
  • Source: Electronics Letters, Volume 27, Issue 10, p. 833 –835
  • DOI:  10.1049/el:19910522
  • Type: Article
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  • p. 833 –835 (3)
    To check the accuracy of the measurements of microwave noise parameters, verification techniques are needed. A common-gate cold FET is proposed as a noise verification standard which presents the advantage of good availability and insertability in the same test jig as employed for packaged active devices. In addition the noise parameters of a common-gate cold FET are of the same order of magnitude as the active device ones. The presented experimental data show an accuracy better than 0.1 dB on the minimum noise figure measurement.
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High sensitivity 10 Gbit/s optical receiver using two cascaded EDFA preamplifiers
Three-probe microstrip measuring system for S-parameter measurements
1.5 μm compressive-strained multiquantum-well waveguide detectors for coherent polarisation-diversified receivers
  • Author(s): C.E. Zah ; K.W. Cheung ; R. Bhat ; N.C. Andreadakis ; T.C. Wu ; F.J. Favire ; S.G. Menocal ; M.A. Koza ; T.P. Lee
  • Source: Electronics Letters, Volume 27, Issue 10, p. 838 –839
  • DOI:  10.1049/el:19910525
  • Type: Article
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  • p. 838 –839 (2)
    The fabrication and polarisation characteristics of 1.5 μm waveguide detectors with compressive-strained multiple quantum wells are reported for the first time. The internal quantum efficiency for the TE mode is estimated to be close to 100% and the absorption loss for the TM mode is estimated to be 4dB. By the use of TE-polarised w4aveguide detectors, a new polarisation-diversified receiver suitable for monolithic integration is proposed.
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Decoding scheme for constant weight codes for optical and spread spectrum applications
Extended transconductance adjustment/linearisation technique
LINC transmitter
Ultrasonic powder-transportation using a pair of phase-shifted bending vibrators
Alternative computation of attenuation in microstrip
Selfguided beam interaction: method of invariants
1.3 μm InGaAsP ridge waveguide laser on GaAs and silicon substrates by thin-film transfer
  • Author(s): C.L. Shieh ; J.Y. Chi ; C.A. Armiento ; P.O. Haugsiaa ; A. Negri ; W.I. Wang
  • Source: Electronics Letters, Volume 27, Issue 10, p. 850 –851
  • DOI:  10.1049/el:19910532
  • Type: Article
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  • p. 850 –851 (2)
    A new thin-film transfer technique has been developed that eliminates the handling of fragile, free-standing films. This process was used to demonstrate the first long wavelength laser fabricated on a host substrate by a thin-film transfer technique. Ridge waveguide lasers operating at a wavelength of 1.3 μm were fabricated on both GaAs and silicon substrates. The light-current characteristics of these transferred lasers were comparable to conventional lasers.
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Low-cost fibre optic tree couplers with applications to communication and sensing distribution networks
10 Gbit/s, 50 km dispersive fibre transmission experiment using strained multiquantum-well DFB laser diode
Efficient hardware decoding method for modified Huffman code
New channelised coplanar waveguide to rectangular waveguide post and slot couplers
All-optical pulse compression using amplifying Sagnac loop
  • Author(s): R.A. Betts ; S.J. Frisken ; C.A. Telford ; P.S. Atherton
  • Source: Electronics Letters, Volume 27, Issue 10, p. 858 –860
  • DOI:  10.1049/el:19910537
  • Type: Article
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  • p. 858 –860 (3)
    The transmission characteristics of a novel amplifying Sagnac loop incorporating an erbium doped fibre amplifier and a semiconductor laser amplifier are reported. The transmission characteristics of such loops at low input powers (< 25 μW in this device) have a nonlinear (approximately cubic) form which has been characterised experimentally and used for all-optical pulse shaping and pulse compression. Optical pulses have been compressed down to 150 ps with a typical single pass compression factor of 0.7.
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Cryogenic operation of GaAs bipolar transistors with inverted base doping
Novel operation of ferrite loaded coaxial lines for pulse sharpening applications
10 Gbit/s MQW-DFB-SIBH lasers entirely grown by LPMOVPE
  • Author(s): P. Speier ; J. Bouayad-Amine ; U. Cebulla ; K. Dütting ; M. Klenk ; G. Laube ; H.P. Mayer ; R. Weinmann ; K. Wünstel ; E. Zielinski ; O. Hildebrand
  • Source: Electronics Letters, Volume 27, Issue 10, p. 863 –864
  • DOI:  10.1049/el:19910540
  • Type: Article
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  • p. 863 –864 (2)
    The successful realisation of MQW DFB-SIBH lasers for 10Gbit/s systems applications is reported. The SIBH laser structure is completely based on an LPMOVPE growth process, including selective LPMOVPE of semi-insulating current blocking layers. Threshold currents as low as 7 mA and total chip capacitances of 2.6 pF are measured resulting in 6dBel (dBel = electrical dB) corner frequencies in excess of 11 GHz and rise/fall times of 36/44 ps, respectively. A significant reduction of the linewidth broadening compared to bulk lasers is observed which is attributed to a reduced α factor due to quantum wells. A chirp at – 20 dB of 0.47 nm under 10Gbit/s modulation is obtained.
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Performance characteristics of strained layer InGaAs/GaAs broad area and ridge waveguide lasers
  • Author(s): B. Saint-Cricq ; S. Bonnefont ; R. Azoulay ; L. Dugrand
  • Source: Electronics Letters, Volume 27, Issue 10, p. 865 –866
  • DOI:  10.1049/el:19910541
  • Type: Article
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  • p. 865 –866 (2)
    Strained layer InGaAs/GaAs single quantum well lasers were fabricated by metal organic vapour phase epitaxy. A broad area threshold current density of 126 A/cm2 as measured for the 1200 μm long devices. Low transparency current density and internal loss were deduced from the study of lasers with different cavity lengths and from using a logarithmic gain-current relation. Variation of the emission wavelength with the cavity length was demonstrated. From this wafer, low threshold ridge waveguide lasers emitting at 984 nm were fabricated that have a potential application as pump sources for erbium doped fibre amplifiers.
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Hybrid ARQ scheme using TCM and code combining
Comment: A step towards determining transient response of chiral materials: Kramers-Kronig relations for chiral parameters
Reply: A step towards determining transient response of chiral materials: Kramers-Kronig relations for chiral parameters
Measured scattered signals at 4 GHz confirm strong specular reflections off buildings
Planar integration of joint transform correlators
  • Author(s): A.K. Ghosh ; M.B. Lapis ; D. Aossey
  • Source: Electronics Letters, Volume 27, Issue 10, p. 871 –872
  • DOI:  10.1049/el:19910546
  • Type: Article
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  • p. 871 –872 (2)
    Planar integration of diffractive-reflective optical systems around a glass substrate is an important concept for efficient, reliable, and compact packaging of optical interconnects. Realisation of joint transform correlators in planar integrated packages is described. Such compact correlator packages can be combined with other integrated packages on an optoelectronic breadboard to build complex optical processors for target recognition applications.
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Class AB switched-current memory for analogue sampled-data systems
Extremely reduced nonlinear K-factor in high-speed strained layer multiquantum well DFB lasers
Capacitive-access CAM cell and its read/write circuit implementation
  • Author(s): S.M.S. Jalaleddine  and  L.G. Johnson
  • Source: Electronics Letters, Volume 27, Issue 10, p. 876 –878
  • DOI:  10.1049/el:19910549
  • Type: Article
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  • p. 876 –878 (3)
    The implementation of a capacitive-access CAM cell along with its read/write circuitry are presented. Its advantages over a standard CAM cell are: feasibility of implementing multicell write operation, ready availability of masking of individual bits of a word for the write operation, and a higher order of cell data stability. A fully functional chip has been fabricated through MOSIS using 2 μm double-metal CMOS technology.
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5 Gbit/s soliton propagation over 350 km with large periodic dispersion coefficient perturbations using erbium doped fibre amplifier repeaters
  • Author(s): A.D. Ellis ; J.D. Cox ; D. Bird ; J. Regnault ; J.V. Wright ; W.A. Stallard
  • Source: Electronics Letters, Volume 27, Issue 10, p. 878 –880
  • DOI:  10.1049/el:19910550
  • Type: Article
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  • p. 878 –880 (3)
    Propagation of 20 ps pulses over 357 km of fibre using erbium doped fibre amplifiers is reported. The pulses are shown to exhibit soliton like propagation, by virtue of their unmodified temporal profile. This is achieved despite the fact that the pulses were propagated through fibre where the dispersion coefficient alternated between −0.2 ps/nm/km and +14ps/nm/km, and a large amplifier spacing of 71 km was employed.
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Millimetre wave quasioptical power combiner
  • Author(s): J.X. Ge ; S.F. Li ; Y.Y. Chen
  • Source: Electronics Letters, Volume 27, Issue 10, p. 880 –882
  • DOI:  10.1049/el:19910551
  • Type: Article
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  • p. 880 –882 (3)
    A new configuration of millimetre wave quasioptical power combiner is demonstrated. It consists of two or more single-cavity multiple-device power combiners and a Fabry-Perot cavity. Because of the improved impedance-matching of diodes and increased injection-locking power, the total output power and combining efficiency of the system are significantly raised. The experimental results from Ka-band models of the quasioptical power combiner are presented.
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Optical-intensity dependent switching using soliton self-frequency shift
  • Author(s): J.K. Lucek  and  K.J. Blow
  • Source: Electronics Letters, Volume 27, Issue 10, p. 882 –884
  • DOI:  10.1049/el:19910552
  • Type: Article
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  • p. 882 –884 (3)
    The soliton self-frequency shift is used to obtain ultrafast all-optical intensity dependent switching. A 10.6 km long telecommunications fibre, a diffraction grating and two detectors are set up in such a way that the power dependence of the soliton self-frequency shift results in nonlinear transfer characteristics. One of the detectors detects 55% of the energy emerging from the fibre at high launched powers and none at low launched powers.
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Comment: Simplification of system model in time domain using continued fraction expansion in third Cauer form
Unique laser diode module using short tapered hemispherical-end fibre for optical hybrid integration
Optical feedback receiver with sensitivity of −55.2 dBm at 8 Mbit/s
Passively mode-locked erbium-doped fibre laser with nonlinear fibre mirror
Phase dependent forward three wave amplification in photorefractive BSO
Erratum: Stability and convergence behaviour of second-order LMS Volterra filter

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