Showing papers in "Electronics Letters in 1995"
TL;DR: In this article, a silicon on insulator material technology based on wafer bonding is described, in which a heat treatment induces an in-depth microslicing of one of the two bonded wafers previously implanted with hydrogen.
Abstract: A silicon on insulator material technology based on wafer bonding is described, in which a heat treatment induces an in-depth microslicing of one of the two bonded wafers previously implanted with hydrogen. The basic phenomena, and the first physical and electrical characterisations are discussed briefly.
1,106 citations
TL;DR: In this article, a coaxially-fed single-layer single-patch wideband microstrip antenna in the form of a rectangular patch with a U-shaped slot is discussed, achieving 10-40% impedance bandwidth without the need of adding parasitic patches in another layer or in the same layer.
Abstract: A coaxially-fed single-layer single-patch wide-band microstrip antenna in the form of a rectangular patch with a U-shaped slot is discussed. Measurements showed that this antenna can attain 10-40% impedance bandwidth without the need of adding parasitic patches in another layer or in the same layer.<
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742 citations
TL;DR: In this paper, full 2D photonic bandgaps are demonstrated for all polarisations in structures with refractive index contrast as small as that of silica and air, and a new type of optical fiber based on these structures is proposed.
Abstract: Full 2-D photonic bandgaps are demonstrated for all polarisations in structures with refractive index contrast as small as that of silica and air. They occur for light propagating out of the transverse plane, with a longitudinal component of wave vector. A new type of optical fibre based on these structures is proposed.
472 citations
TL;DR: In this paper, the advantages of microstrip patch technology over its competitors is its low profile and hence small volume, and the relative ease in which it can be connected to the feed network, as was highlighted in Chapter 2.
Abstract: As stated in Chapter 1, one of the many advantages of microstrip patch technology over its competitors is its low profile and hence small volume. Another key advantage of this printed antenna is the relative ease in which it can be connected to the feed network, as was highlighted in Chapter 2. For these reasons antenna design engineers deduced that microstrip patch antennas could be utilized for applications requiring where there was very limited space to mount the antenna. One such global application is for wireless communication handset terminals.
399 citations
TL;DR: In this paper, the impact of chromatic dispersion in optical millimetre-wave systems operating in the 1.55 µm wavelength window was investigated. But the effect of dispersion on the performance of optical modulators was not considered.
Abstract: The author reports the impact of chromatic dispersion in optical millimetre-wave systems operating in the 1.55 µm wavelength window. Experimental and theoretical results confirm the dramatical millimetre-power degradation in conventional amplitude modulated systems using, for example, external optical modulators. In comparison, by use of a similar setup a self-heterodyne-based system concept has been investigated showing negligible dependence on the chromatic dispersion.
395 citations
TL;DR: In this paper, an index-guided vertical cavity top-surface emitting laser diodes have been fabricated from an all epitaxial structure with conducting mirrors by selective lateral oxidation of AlGaAs.
Abstract: Index-guided vertical cavity top-surface emitting laser diodes have been fabricated from an all epitaxial structure with conducting mirrors by selective lateral oxidation of AlGaAs At low voltage, a 78% slope efficiency, and a 350 mu A threshold current in a single device combine to yield a maximum power conversion efficiency of 50% at less than a 2 mA drive current The device operates in a single mode up to 15 mW >
388 citations
TL;DR: In this paper, the InGaAs single quantum well vertical-cavity surface-emitting laser with an intracavity p-contact fabricated by selective oxidation of AlAs and distributed Bragg reflectors composed of binary materials (AlAs/GaAs).
Abstract: The authors report InGaAs single quantum well vertical-cavity surface-emitting lasers with an intracavity p-contact fabricated by selective oxidation of AlAs and distributed Bragg reflectors composed of binary materials (AlAs/GaAs). Record low threshold currents of 8.7 µA in ~3 µm square devices and 140 µA in 10 µm square devices with maximum output powers over 1.2 mW are achieved.
357 citations
TL;DR: A Si single electron transistor (SET) was fabricated by converting a one-dimensional Si wire on a SIMOX substrate into a small Si island with a tunnelling barrier at each end by means of pattern-dependent oxidation.
Abstract: A Si single electron transistor (SET) was fabricated by converting a one-dimensional Si wire on a SIMOX substrate into a small Si island with a tunnelling barrier at each end by means of pattern-dependent oxidation. With this structure, the total capacitance was reduced to approximately 2aF, which enabled conductance oscillation of the SET at room temperature.
349 citations
TL;DR: In this article, a novel soliton transmission scheme to suppress the accumulation of the Gordon-Haus jitter using periodic dispersion compensation and inline optical filters has been proposed, achieving a Q/sup 2/ of 19 dB and a large power window of 2 dB.
Abstract: A novel soliton transmission scheme to suppress the accumulation of the Gordon-Haus jitter using periodic dispersion compensation and inline optical filters has been proposed. With 90% dispersion compensation rate and optimum optical filters, a Q/sup 2/ of 19 dB and a large power window of 2 dB were confirmed for a 20 Gbit/s, 9000 km transmission system by using a 1000 km-long recirculating loop.
293 citations
TL;DR: In this paper, the first observation of two-dimensional steady-state photorefractive solitons with diameters as small as 9.6 mu m at microwatt power levels was reported.
Abstract: The first observation of two-dimensional steady-state photorefractive solitons is reported. Application of an electric field of 5.8 kV/cm to strontium barium niobate yields solitons with diameters as small as 9.6 mu m at microwatt power levels. >
253 citations
TL;DR: In this paper, a new and flexible technique for producing photorefractive fiber gratings with a uniform phase mask is demonstrated, by slowly moving the fiber relative to the mask as the writing beam is scanned, wavelength shifts, pure apodisation and phase-shifted gratings can be achieved.
Abstract: A new and flexible technique for producing photorefractive fibre gratings with a uniform phase mask is demonstrated. By slowly moving the fibre relative to the mask as the writing beam is scanned, wavelength shifts, pure apodisation and phase-shifted gratings can be achieved.
TL;DR: A new concept to take advantage of the parasitic resistance that appears on port X of the second-generation current conveyors is introduced, and a current controlled bandpass filter, operating in the current mode, is described.
Abstract: A new concept to take advantage of the parasitic resistance that appears on port X of the second-generation current conveyors is introduced. This parasitic resistance, which is controllable in current, leads to the definition of the second generation current controlled conveyors (CCCII). A current controlled bandpass filter, operating in the current mode, is also described. It uses only two CCCII+s and two capacitors. Its central frequency can be adjusted by acting on the bias current of the conveyors. SPICE simulation results, in agreement with theory, are given for central frequencies around 30 MHz.
TL;DR: In this paper, the authors demonstrate dispersion compensation at two different wavelengths with such a grating in a 240 km fiber link using a 10 Gbit/s externally modulated laser source.
Abstract: Chirped sampled fibre Bragg gratings have a dispersion that repeats itself periodically, and can thus be used for dispersion compensation over a broad bandwidth, or for multiple channels in WDM systems. The authors demonstrate dispersion compensation at two different wavelengths with such a grating in a 240 km fibre link using a 10 Gbit/s externally modulated laser source.
TL;DR: In this article, a new type of dual-mode microstrip square loop resonator was proposed for the design of compact microwave bandpass filters and the associated characteristics of mode splitting were described.
Abstract: A new type of dual-mode microstrip square loop resonator is proposed for the design of compact microwave bandpass filters. The associated characteristics of mode splitting are described. A novel bandpass filter, consisting of such a dual-mode resonator having a 1.2% bandwidth at 1.52 GHz was designed and fabricated. The measured filter performance is presented.
TL;DR: Simulations indicate that first-order, second-order and bandpass noise-shaping are all possible in the technique that enables the use of multibit feedback in delta-sigma A/D and D/A convertors.
Abstract: By appropriately selecting the elements used to form each output sample of a multibit digital-to-analogue convertor, the spectrum of the error caused by element mismatch can be noise-shaped. Simulations indicate that first-order, second-order and bandpass noise-shaping are all possible. The technique enables the use of multibit feedback in delta-sigma A/D and D/A convertors.
TL;DR: In this article, an index-guided InGaAs/GaAlAs vertical-cavity surface-emitting laser with a native oxide confinement structure has been proposed and fabricated.
Abstract: An index-guided InGaAs/GaAlAs vertical-cavity surface-emitting laser with a native oxide confinement structure has been proposed and fabricated. A record threshold current of 70 µA was achieved with a 5 µm-diameter core device. The proposed structure provides strong electrical and optical confinements. Also a reduction in nonradiative recombination and an improvement in the thermal resistance can be expected.
TL;DR: The third generation current conveyor (CCIII) as mentioned in this paper is a new conveyor which has been defined from the general equations that describe the first and second-generation current conveyors, and its class AB implementation, obtained from two second generation current conveys, is given, the circuits being implemented from complementary bipolar arrays.
Abstract: A new conveyor, which has been called the third generation current conveyor (CCIII), is introduced. It is defined from the general equations that describe the first and second generation current conveyors. As an example of its possibilities, the use of the circuit as a floating current sensing device is investigated. Its class AB implementation, obtained from two second generation current conveyors, is given. Some simulation results are also reported, the circuits being implemented from complementary bipolar arrays.
TL;DR: In this article, an apodised in-fibre Bragg grating reflector is fabricated using the phase mask photoimprinting technique, which has a center wavelength of 1550 nm, a bandwidth of 0.22 nm and a peak reflectivity of 90%.
Abstract: An apodised in-fibre Bragg grating reflector is fabricated using the phase mask photoimprinting technique. The reflector has a centre wavelength of 1550 nm, a bandwidth of 0.22 nm and a peak reflectivity of 90%. At 0.4 nm (50 GHz) from the centre wavelength the reflectivity is 40 dB lower than the peak reflectivity; this is an improvement of more than 20 dB over an unapodised Bragg grating reflector with similar bandwidth and peak reflectivity.
TL;DR: In this paper, an all solid state, VLSI compatible, electroluminescent device based on porous silicon with an external quantum efficiency greater than 0.1% under CW operation was presented.
Abstract: The authors report an all solid state, VLSI compatible, electroluminescent device based on porous silicon with an external quantum efficiency greater than 0.1% under CW operation. The emission, which is broadband and peaks at 600 nm, is detected above a low threshold current density and voltage of 0.01 Am-2 and 2.3 V, respectively.
TL;DR: In this paper, a surface normal micromachined GaAs Fabry-Perot filter with 70 nm of continuous tuning, 19 dB extinction ratio, 4.9 V of tuning voltage, and 50 pA tuning current is presented.
Abstract: The authors present a surface-normal micromachined GaAs Fabry-Perot filter with 70 nm of continuous tuning, 19 dB extinction ratio, 4.9 V of tuning voltage, and 50 pA tuning current. The device is polarisation insensitive, can be fabricated into two-dimensional arrays, is easy to couple into fibre, and requires only two masks with no critical alignments.
TL;DR: In this article, a low-loss, highly efficient, single-mode optical phase modulator in SOI is reported, and the induced phase shift per volt per millimetre, is greater than 200 degrees /V/mm.
Abstract: The realisation of a low-loss, highly efficient, single-mode optical phase modulator in SOI is reported. At a wavelength of 1.5 mu m the figure of merit for the device, the induced phase shift per volt per millimetre, is greater than 200 degrees /V/mm. To our knowledge, this is the highest reported value to date. In addition, the device drive current ( >
TL;DR: In this article, the core radius is made non-uniform along its length to utilize the core-radius dependence of the longitudinal acoustic frequency, and the effective Brillouin gain of an SBS suppression fiber prepared by the VAD method was reduced by 3.5 dB compared with conventional fibres.
Abstract: Stimulated Brillouin scattering (SBS) in a fibre is suppressed by making the core radius nonuniform along its length to utilise the core-radius dependence of the longitudinal acoustic frequency. The effective Brillouin gain of an SBS suppression fibre prepared by the VAD method was reduced by 3.5 dB compared with conventional fibres.
TL;DR: The authors report the first demonstration of all-optical header recognition and self-routing of ultrafast packets with multibit addresses and a single optical AND gate recognises 6 bit ‘keyword’ codes, allowing self- routing of 100 Gbit/s packets.
Abstract: The authors report the first demonstration of all-optical header recognition and self-routing of ultrafast packets with multibit addresses. A single optical AND gate recognises 6 bit ‘keyword’ codes, allowing self-routing of 100 Gbit/s packets. [This Letter first appeared in print in 1995, issue 17, p.1475–1476, and has been reprinted because of the significance of the corrections.]
TL;DR: Turbo codes can be used for channels where some information bits are more sensitive to errors than others, and at the same time where powerful codes are required (e.g. a mobile satellite channel).
Abstract: Turbo codes can easily be used when two error protection levels are needed. The same encoder and decoder is used to achieve this unequal error protection. This will allow turbo codes to be used for channels where some information bits are more sensitive to errors than others, and at the same time where powerful codes are required (e.g. a mobile satellite channel).
TL;DR: In this paper, the authors reported the highest electro-optic effect measured in a germanosilicate fiber ever reported, which was induced by UV-excited poling at 193 nm with an electric field >8*10/sup 5/V/cm.
Abstract: The authors report what is, to their knowledge, the highest electro-optic effect measured in a germanosilicate fibre ever reported. The electro-optic effect based on a permanent second-order nonlinearity has been induced by UV-excited poling at 193 nm with an electric field >8*10/sup 5/ V/cm. Polarisation dependence of the V/sub pi /L product in a birefringent fibre has been observed, and the lowest V/sub pi /L product obtained for the TE mode of 32 Vcm, comparable to that based on r/sub 22/ of LiNbO/sub 3/, has been measured at 633 nm with a phase modulation at frequencies up to 5 MHz. >
TL;DR: Transverse v-grooves, directly formed into the side of an optical fiber, totally reflect light incident on the fiber side-wall, directing it along the fibre axis.
Abstract: Transverse v-grooves, directly formed into the side of an optical fibre, totally reflect light incident on the fibre side-wall, directing it along the fibre axis. For a 96 µm core fibre, light incident from a laser diode is coupled into the fibre by the v-groove with 96% coupling efficiency.
TL;DR: In this paper, a technique for demodulation of fiber Bragg grating (FBG) sensor arrays that uses a matched grating array to optically filter and track wavelength shifts from the FBG sensors is demonstrated.
Abstract: A technique for the demodulation of fibre Bragg grating (FBG) sensor arrays that uses a matched grating array to optically filter and track wavelength shifts from the FBG sensors is demonstrated. The use of matched grating arrays in the serial configuration represents an efficient and potentially low-cost interrogation technique for FBG sensors.
TL;DR: In this paper, an adaptive technique is presented that produces array pattern troughs in response to discrete interference sources, which applies a transform to the sample covariance matrix that synthesises dispersion, thus making the interferers appear to cover a greater angular extent.
Abstract: An adaptive technique is presented that produces array pattern troughs in response to discrete interference sources. The technique applies a transform to the sample covariance matrix that synthesises dispersion, thus making the interferers appear to cover a greater angular extent.
TL;DR: In this article, an adaptive technique is presented that produces array pattern troughs in response to discrete sources of interference, which is implemented by a simple modification of the measured covariance matrix.
Abstract: An adaptive technique is presented that produces array pattern troughs in response to discrete sources of interference. The technique is implemented by a simple modification of the measured covariance matrix, and results in forming similar troughs centred at all sources of interference.
TL;DR: In this paper, a temperature-independent strain sensor was demonstrated using a chirped fiber grating in a tapered optical fiber. But the effective bandwidth of the grating is uniquely dependent on strain and is essentially temperature independent.
Abstract: A novel, temperature-independent strain sensor is demonstrated using a chirped fibre grating in a tapered optical fibre. The effective bandwidth of the grating is uniquely dependent on strain and is essentially temperature-independent. The interrogation simply involves monitoring the back-reflected intensity from the grating. A strain resolution of 0.1% over a strain measurement range of 4066 mu epsilon has been experimentally achieved. >