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• 1.7 Gbit/s transmission over 165 km of dispersion-shifted fibre using spectrum-sliced fibre amplifier light source

Publication Year: 1994, Page(s):1427 - 1428
Cited by:  Papers (5)  |  Patents (1)
| | PDF (184 KB)

The authors have demonstrated 1.7 Gbit/s transmission over 165 km of dispersion-shifted fibre using a spectrum-sliced fibre amplifier light source. To the authors' knowledge, this represents the largest bit-rate distance product (280 Gbit/s km) ever demonstrated using an incoherent light source. The dispersion penalty was very small (~0.3 dB) even at a wavelength 10 nm away from the dispersion-zer... View full abstract»

• Distance limits of 10 to 20 Gbit/s FSK transmission on standard fibre

Publication Year: 1994, Page(s):1428 - 1430
Cited by:  Papers (2)
| | PDF (272 KB)

A simple analysis is performed on an FSK transmission system using a high FM efficiency, high bandwidth DFB laser as a simple DFB transmitter and an FM/AM converter as an optical signal processor. It shows that optimum optical processing pushes the transmission limits to 150 km at 10 Gbit/s and to 40 km at 20 Gbit/s View full abstract»

• Millimetre-wave signal generation using pulsed semiconductor lasers

Publication Year: 1994, Page(s):1430 - 1431
Cited by:  Papers (22)  |  Patents (5)
| | PDF (184 KB)

A novel technique for millimetre-wave signal generation using a pulsed semiconductor laser is proposed and demonstrated. Optical filtering is used to select only two modes and suppress all other modes in the optical spectrum of the laser. The two selected modes beat together in a photodiode to generate a millimetre-wave signal with 100% modulation depth View full abstract»

• Kink-like effect in long n-channel twin-gate fully-depleted SOI MOSFETs

Publication Year: 1994, Page(s):1456 - 1458
Cited by:  Patents (2)
| | PDF (232 KB)

Twin-gate structures consisting of the series combination of two short-channel SOI MOSFETs of different lengths with a common gate have previously demonstrated kink-free and very flat output characteristics. The authors observe and explain that when using long-channel fully-depleted twin-gates a kink-like effect reappears and seriously damages the output conductance View full abstract»

• Multichannel FM-TV transmission using an engineered 1.3 μm praseodymium-doped fluoride fibre amplifier

Publication Year: 1994, Page(s):1431 - 1432
Cited by:  Papers (4)
| | PDF (184 KB)

The authors report the first use of a praseodymium-doped fluoride fibre amplifier (PDFFA) in a 24 TV channel FM-SCM transmission experiment. Twenty-four analogue FM-SCM-TV channels were amplified by a PDFFA without any observable degradation in picture quality. By using a single PDFFA as a post-amplifier, transmission over 104 km of standard' 1.3 μm optimised fibre was demonstrated with a tota... View full abstract»

• Fast square-and-multiply exponentiation for RSA

Publication Year: 1994, Page(s):1396 - 1397
Cited by:  Papers (6)  |  Patents (3)
| | PDF (188 KB)

The authors describe a practical technique for improving the performance of square-and-multiply exponentiation. A family of linear time algorithms denoted by SS(l) where l determines the maximum length of precomputed exponents, is presented. Analysis on n-bit exponents shows that the average number of multiplications required tends to nl(l+1) for large n View full abstract»

• Integrated optics for optical head applications

Publication Year: 1994, Page(s):1403 - 1404
Cited by:  Patents (5)
| | PDF (172 KB)

A waveguide structure for use in optical head systems is presented. The fabricated structures are 10×2×2 mm3 and are <0.2 g in mass. The waveguides propagate data and feedback signals for tracking and focusing. The proper generation of these signals and their sensitivity to the accompanying imaging optics are demonstrated View full abstract»

• Optimisation of coded frequency and phase modulation

Publication Year: 1994, Page(s):1384 - 1385
| | PDF (152 KB)

The Letter is concerned with the optimisation of coded frequency and phase modulation (FPM). Two approaches to optimisation are presented and their improvements over the normal coded FPM are investigated. The analytic and simulation results show that the additional gains due to optimisation can be achieved with little or no loss View full abstract»

• High power, high gain optical fibre amplifier for multiwavelength transmission systems

Publication Year: 1994, Page(s):1411 - 1413
Cited by:  Papers (7)  |  Patents (7)
| | PDF (256 KB)

A new type of optical fibre amplifier, a hybrid amplifier', especially developed for multiwavelength long distance transmission systems in the 1.55 μm window is presented. A 38 dB small signal gain, an +18 dBm saturation output power, a very flat gain spectrum and a very big signal-to-noise-ratio are obtained View full abstract»

• MOSFET threshold extraction from voltage-only measurements

Publication Year: 1994, Page(s):1458 - 1459
Cited by:  Papers (3)  |  Patents (1)
| | PDF (128 KB)

The authors describe a method for determining the MOS transistor parameters from voltage measurements by considering two transistors in series. The voltage characteristics at the intermediate node of the two connected transistors allow easy and direct determination of the threshold voltage, the pinch-off voltage and the slope factor View full abstract»

• Class of algebraically constructed permutations for use in pseudorandom interleavers

Publication Year: 1994, Page(s):1378 - 1379
Cited by:  Papers (4)  |  Patents (27)
| | PDF (156 KB)

The author shows that Lempel-Costas (LC) arrays when treated as permutations possess ideal properties for use in pseudorandom interleavers. The basic theory of interleavers is reviewed and the necessary conditions imposed on permutations for successful operation of pseudorandom interleavers are given. Proof that LC arrays satisfy the conditions, and a comparison with randomly constructed permutati... View full abstract»

• Bend loss in buffered over-moded optical fibre: LP11 mode and whispering gallery' mode interaction

Publication Year: 1994, Page(s):1433 - 1434
Cited by:  Papers (3)
| | PDF (176 KB)

Bend loss in over-moded fibre has been measured as a function of temperature. For the LP11 mode, an oscillatory loss dependence on temperature was observed, caused by coupling between the LP11 mode and a whispering gallery' mode. These interactions could have a significant effect on singlemode cutoff wavelength measurements View full abstract»

• Fabrication of 2-D photonic bandgap structures in GaAs/AlGaAs

Publication Year: 1994, Page(s):1444 - 1446
Cited by:  Papers (12)  |  Patents (6)
| | PDF (264 KB)

The authors report the first realisation of a two-dimensional photonic bandgap structure with a period of λ0/2n in the GaAs/AlGaAs material system. The structure consists of a honeycomb lattice with a wall thickness of ~30 nm and a period of 160 nm. It was found that, to realise patterns of such small size and periodicity, it is crucial to control the shape of the exposed feature... View full abstract»

• Two-mode fibre spatial-mode converter using periodic core deformation

Publication Year: 1994, Page(s):1437 - 1438
Cited by:  Papers (9)  |  Patents (3)
| | PDF (176 KB)

Efficient conversion between the LP01 and LP11 modes in a two-mode fibre is achieved by periodically ablating the fibre surface with a CO2 laser and then annealing the fibre with an electric arc. The resulting periodic core deformation produces 99% mode conversion over a 37 nm bandwidth around 1540 nm and 0.38 dB insertion loss View full abstract»

• Logarithmic speed modular multiplication

Publication Year: 1994, Page(s):1397 - 1398
Cited by:  Papers (5)
| | PDF (192 KB)

A design for logarithmic speed modular multiplication is given and a quantitative comparison made with the best implementations of existing, more standard algorithms. A 40-fold increase in speed is reported using a chip area at the limit of current technology View full abstract»

• 0.85 μm bottom-emitting vertical-cavity surface-emitting laser diode arrays grown on AlGaAs substrates

Publication Year: 1994, Page(s):1406 - 1407
Cited by:  Papers (2)  |  Patents (5)
| | PDF (196 KB)

The first 0.85 μm 8×8 bottom-emitting vertical-cavity surface emitting laser diodes (VCSELs) have been grown on AlGaAs substrates. Their characteristics are the same as those of VCSELs grown on GaAs substrate. The authors have also fabricated 8×8 independently addressable VCSEL arrays which exhibited good lasing characteristics and uniform threshold current density View full abstract»

• Results of 11.6 GHz radiometric experiment in Cameroon: second year

Publication Year: 1994, Page(s):1449 - 1450
Cited by:  Papers (1)
| | PDF (172 KB)

Three experiments were set up within a joint African radiometric propagation measurement program to provide data at frequencies above 10 GHz for predictive modelling. The authors report the results of the second year of measurements in Douala, Cameroon, along with mean results for the two years. These show significant departures from the ITU-R (formerly CCIR) rain climate and path attenuation mode... View full abstract»

• Stability and throughput optimisation of multichannel slotted nonpersistent CSMA random choice protocol

Publication Year: 1994, Page(s):1387 - 1388
Cited by:  Papers (1)
| | PDF (180 KB)

The analysis of stability and throughput optimisation of a multichannel multiaccess slotted nonpersistent CSMA random choice protocol for infinite population is examined. The proposed protocol is an extension of the slotted single channel nonpersistent CSMA protocol with random selection policy of the channel in which a station (re)transmits. Optimisation rules are derived which show that the opti... View full abstract»

• High speed, ultralow noise, tensile strained InGaAlAs MQW lasers emitting at 1300 nm for optical communication and microwave applications

Publication Year: 1994, Page(s):1413 - 1414
Cited by:  Papers (6)  |  Patents (2)
| | PDF (164 KB)

Tensile strained InGaAlAs multiquantum well lasers emitting at 1300 nm have been developed by using a ridge waveguide structure. The lasers demonstrate >20 GHz modulation bandwidth and very low relative intensity noise of -150 dBm/Hz. 10 dB improvement in optical link loss has been observed compared to previously reported results for microwave lasers in the InGaAsP system View full abstract»

• Forward link power control for cellular CDMA networks. Comment & Reply

Publication Year: 1994, Page(s):1379 - 1380
| | PDF (160 KB)

M.M.Wang and O.K.Tonguz (see ibid., vol.29, pp.1195-1197, 1993) studied the power control issue with reference to the base-to-mobile link of a cellular CDMA system in the presence of fading. The performance of the system was given for various values of the power control law exponent, and for two different models for the traffic distribution, i.e. uniform and truncated bell. The authors comment on ... View full abstract»

• Loss distribution measurement of silica-based waveguides by using a jaggedness-free optical low coherence reflectometer

Publication Year: 1994, Page(s):1441 - 1443
Cited by:  Papers (6)  |  Patents (9)
| | PDF (272 KB)

The loss distributions in silica-based waveguides are successfully measured using a jaggedness-free optical reflectometer (OLCR). The OLCR reduces jagged fluctuations which appear in Rayleigh backscattering measurements undertaken with conventional OLCRs to within ±1 dB by averaging the wavelength-dependent Rayleigh backscatter signals. Constant loss distributions and a step-like loss incre... View full abstract»

• Nonlinear influence on PM-AM conversion measurement of group velocity dispersion in optical fibres

Publication Year: 1994, Page(s):1434 - 1435
Cited by:  Papers (18)  |  Patents (5)
| | PDF (184 KB)

The authors propose a method for measuring the group velocity dispersion, including the polarity, of optical fibre by using a single wavelength light source. The method is based on the interplay between phase modulation-amplitude modulation (PM-AM) conversion and self-phase modulation (SPM) View full abstract»

• Monolithically integrated polarisation diversity heterodyne receivers on GaInAsP/InP

Publication Year: 1994, Page(s):1446 - 1447
Cited by:  Papers (10)
| | PDF (192 KB)

Polarisation diversity heterodyne receiver OEICs including a tunable four-section DBR laser as a focal oscillator have been successfully fabricated for the first time. OEIC design and fabrication are described and first characteristics of the integrated subcomponents and a packaged receiver OEIC are presented View full abstract»

• Compact quartzless optical quasi-circulator

Publication Year: 1994, Page(s):1438 - 1440
Cited by:  Papers (1)  |  Patents (5)
| | PDF (272 KB)

A compact quartzless structure is proposed for polarisation-insensitive optical quasi-circulators. Quartz is eliminated by using two different materials, YIG and GBIG in a Faraday rotator. The signs of their Faraday rotation coefficients are reversed. The length of the prototype is only half that of the conventional design for equally high isolation values View full abstract»

• Novel 1-out-of-n CMOS checker

Publication Year: 1994, Page(s):1398 - 1400
Cited by:  Papers (7)
| | PDF (280 KB)

An original concept is presented to implement highly testable and compact 1-out-of-n checkers (for any value of n), that are totally self-checking with respect to a wide set of realistic faults (including resistive bridgings). The case of n=3 is explicitly treated as a significant example View full abstract»

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Electronics Letters is internationally renowned for its rapid communication of new developments and emerging topics across the broad and interdisciplinary field of modern electronics and electrical engineering.

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Meet Our Editors

Editors-in-Chief

Professor Chris Toumazou
Director of the Biomedical Institute
Imperial College, London, UK

Professor Ian White