Showing papers in "Electronics Letters in 1976"
TL;DR: In this article, very low-OH-content optical fibres consisting of borosilicate-cladding phosphosilicate core have been produced by a chemical vapour deposition technique.
Abstract: Very-low-OH-content optical fibres consisting of borosilicate-cladding phosphosilicate-core have been produced by a chemical vapour deposition technique. One of the fibres, whose transmission loss was less than 1 dB/km between 0.95 and 1.37 μm, showed a minimum loss of 0.47 dB/km at 1.2 μm.
285 citations
TL;DR: In this article, the cutoff-frequency/gate-length curves are calculated for uniform and non-uniform channel field distribution in GaAs fets using the fit to the equilibrium Monte Carlo data.
Abstract: A simple model which describes well the nonequilibrium electron transport in GaAs using the fit to the equilibrium Monte Carlo data is suggested In the frame of this model, the cutoff-frequency/gate-length curves are calculated for uniform and nonuniform channel field distribution in GaAs fets The results show that the nonhomogeneity of the electric field in the channel can considerably decrease (by 30%) the maximal frequency of GaAs fets
185 citations
TL;DR: In this paper, the effects of dopants in pure silica on the losses of optical fibres were investigated and the results showed that the effect of the dopants on the loss in the near-infrared region was negligible.
Abstract: We formerly developed very-low-OH-content optical fibres consisting of a borosilicate cladding and a phosphosilicate core. The transmission loss of the fibre was 0.47 dB/km at 1.2 μm. We have further investigated the effects of dopants in pure silica on the losses of fibres. The letter clarifies the effects of dopants on the loss in the near-infrared region.
155 citations
TL;DR: In this article, the attenuation coefficient of cylindrical dielectric-rod waveguide was measured by a transmission method at 100 GHz and an 8 dB/m attenuation was obtained.
Abstract: Measurements have been made of the attenuation coefficient of cylindrical dielectric-rod waveguide by a transmission method at 100 GHz. An 8 dB/m attenuation coefficient was obtained, caused half and half by the absorption due to losses in the dielectric and by the scattering due to irregularities and inhomogeneities in the dielectric.
152 citations
TL;DR: In this paper, experiments have been performed on horizontal shear surface-wave propagation along a corrugated surface and the results are in agreement with approximate theories used in analogous electromagnetic problems.
Abstract: Experiments have been performed on horizontal shear surface-wave propagation along a corrugated surface. The results are in agreement with approximate theories used in analogous electromagnetic problems.
123 citations
TL;DR: In this paper, it was shown that current transport through Schottky barriers formed by Pd on n-type silicon with a thin thermally grown oxide is sensitive to hydrogen in the ambient.
Abstract: It is shown that current transport through Schottky barriers formed by Pd on n-type silicon with a thin thermally grown oxide is sensitive to hydrogen in the ambient. It is shown that a transition from minority- to majority-carrier dominated current occurs with increasing hydrogen pressure.
115 citations
TL;DR: A simple analytic formula for the microbending loss in monomode fibres of arbitrary refractive-index profile is presented in this paper, which essentially depends on the spot size of the fundamental fibre mode only.
Abstract: A simple analytic formula for the microbending loss in monomode fibres of arbitrary refractive-index profile is presented. This loss essentially depends on the spot size of the fundamental fibre mode only. Therefore W-fibres, for example, are as sensitive to microbending as conventional cladded-core fibres.
109 citations
TL;DR: In this article, an optical waveguide 4×4 switching network fabricated by integrating five switched directional couplers with stepped reversal on a single LiNbO3 substrate was reported, where the maximum crosstalk observed on any output waveguide was down by 18 dB.
Abstract: An optical waveguide 4×4 switching network fabricated by integrating five switched directional couplers with stepped ?s reversal on a single LiNbO3 substrate is reported. The maximum crosstalk observed on any output waveguide was down by 18 dB.
87 citations
TL;DR: In this article, a simple method of measuring drift-mobility profiles in semiconductor films is described based on the low-frequency measurement of the transconductance and gate capacitance of an f.t. structure as a function of gate bias.
Abstract: A simple method of measuring drift-mobility profiles in semiconductor films is described. It is based on the low-frequency measurement of the transconductance and gate capacitance of an f.e.t. structure as a function of gate bias. Drift mobilities of 4000 to 5000 cm2/Vs have been measured on n-type GaAs films with 1016 to 1017 cm-3 doping levels.
73 citations
TL;DR: When a stripe-geometry heterostructure GaAlAs laser is irradiated by its own output beam, oscillations in the 1-100 MHz range are generated in the laser, and the frequency f of the oscillation varies with the length 2L of the optical path of the beam returned as f = α(c/2L), with α ≪ 1, where c is the velocity of light as discussed by the authors.
Abstract: When a stripe-geometry heterostructure GaAlAs laser is irradiated by its own output beam, oscillations in the 1–100 MHz range are generated in the laser, and the frequency f of the oscillation varies with the length 2L of the optical path of the beam returned as f = α(c/2L), with α ≪ 1, where c is the velocity of light.
73 citations
TL;DR: In this article, a unique monolithic X-band f.t. amplifier is described, using lumped elements, integrated with the transistor on semi-insulating gallium arsenide to produce an amplifier chip 1.8×1.2 mm.
Abstract: A unique monolithic X-band f.e.t. amplifier is described. Wideband matching circuits, using lumped elements, are integrated with the transistor on semi-insulating gallium arsenide to produce an amplifier chip 1.8×1.2 mm. Gains in excess of 4.5 dB over 7.5 to 11.5 GHz have been measured. The chip has been installed into a low-parasitic package to produce a gain module suitable for the microwave engineer.
TL;DR: In this article, a simple method for direct measurement of the V-value for a single-mode optical fiber was proposed, which consists of measurement of loss peaks, corresponding to cutoff wavelengths of the higher modes, which are easily observed for a fibre with a bend.
Abstract: A simple method is proposed for the direct measurement of the V-value for a single-mode optical fibre. This method consists of measurement of loss peaks, corresponding to cutoff wavelengths of the higher modes, which are easily observed for a fibre with a bend.
TL;DR: In this paper, a p+?p?n+ structure was used to construct a sub-millimetre-wave silicon single-drift region IMPATT diodes with a p +?p n+ structure and the maximum c.w. oscillation frequency was 394 GHz.
Abstract: Submillimetre-wave silicon single-drift-region IMPATT diodes with a p+?p?n+ structure have been fabricated by ion implantation. C.W. output powers of 7.5 mW at 285 GHz and 78 mW at 185 GHz were obtained. The maximum c.w. oscillation frequency observed was 394 GHz.
TL;DR: Reflection, transmission and radiation properties of a step discontinuity on a dielectric surface waveguide are calculated in this article, and the method used involves bounding the open waveguide with perfect conductors.
Abstract: Reflection, transmission and radiation properties of a step discontinuity on a dielectric surface waveguide are calculated The method used involves bounding the open waveguide with perfect conductors Results are compared with those given by previous authors
TL;DR: In this article, the 2nd-order nonlinear distortion of avalanche photodiodes (TIXL-55, C-20817) was found to be less than −60 dB for an incident average optical power of −20 dBm modulated at a peak depth of 75%.
Abstract: The 2nd-order nonlinear distortion of avalanche photodiodes (TIXL-55, C-20817) was found to be less than −60 dB for an incident average optical power of −20 dBm modulated at a peak depth of 75%. p-i-n photodiodes (HP 5082-4207) were found to have 2nd-order-distortion levels below the noise level. A method using three independent optical signal sources was employed in the measurement.
TL;DR: The capacitance/voltage characteristics of the metal-oxide-semiconductor system formed on n-type GaAs by anodic oxidation differ greatly from those of p-type GAAs, showing an anomalous frequency dispersion which is not caused by the Quast carrier diffusion mechanism, but by anomalous formation of interface states as discussed by the authors.
Abstract: The capacitance/voltage characteristics of the metal-oxide-semiconductor system formed on n-type GaAs by anodic oxidation differ greatly from those of p-type GaAs, showing an marked anomalous frequency dispersion which is not caused by the Quast carrier diffusion mechanism, but by an anomalous formation of interface states.
TL;DR: In this article, the authors report a practical approach to the positioning of a number of single-mode fibres for end-fire coupling to channel waveguides, which has been extended to a flip-chip configuration which permits its use with substrates other than silicon.
Abstract: We report a practical approach to the positioning of a number of single-mode fibres for endfire coupling to channel waveguides. Boivin's approach has been extended to a flip-chip configuration which permits its use with substrates other than silicon.
TL;DR: In this paper, a study of propagation in curved single-mode fibres showed that the transmission loss increases sharply below a critical bend radius, however the radiation does not leak away uniformly with distance but in a series of discrete well-defined rays.
Abstract: A study of propagation in curved single-mode fibres shows that the transmission loss increases sharply below a critical bend radius. However the radiation does not leak away uniformly with distance but in a series of discrete well-defined rays.
TL;DR: In this paper, a planar waveguide model for microstrip is used to obtain an improved method of correcting for curvature effects in ring resonators, and the extent of the improvement is illustrated by a comparison of experimental measurements and theoretical predictions of microstrip dispersion.
Abstract: A planar waveguide model for microstrip is used to obtain an improved method of correcting for curvature effects in ring resonators. The extent of the improvement is illustrated by a comparison of experimental measurements and theoretical predictions of microstrip dispersion.
TL;DR: In this article, it was shown that a new technology results in the first native-oxide m.o.s.f.t.s and their electrical behavior is described.
Abstract: It is shown that a new technology results in the first native-oxide m.o.s.f.e.t.s. Their electrical behaviour is described.
TL;DR: A theoretical formula, accounting for parameter mismatch errors, and experimental measurements establish the necessity for using an additional transistor in the widely used Wilson current source if a direct-current transfer ratio centred on unity is to be achieved.
Abstract: A theoretical formula, accounting for parameter mismatch errors, and experimental measurements establish the necessity for using an additional transistor in the widely used Wilson current source if a direct-current transfer ratio centred on unity is to be achieved.
TL;DR: In this paper, a new type of electro-optic channel-waveguide modulator/switch for integrated optics has been proposed and demonstrated in which the transverse confinement of The guided optical wave in a channel waveguide is controlled and the optical energy is selectively fed to either Y-junction output port by control of the applied electric field.
Abstract: A new type of electro-optic channel-waveguide modulator/switch for integrated optics has been proposed and demonstrated in which the transverse confinement of The guided optical wave in a channel waveguide is controlled and the optical energy is selectively fed to either Y-junction output port by control of the applied electric field. The device exhibited 75% modulation depth for an applied voltage swing of 6 V peak to peak and a potential bandwidth of 10 GHz.
TL;DR: Optical waveguiding has been demonstrated in planar Structures fabricated with long-chain organic molecules deposited by the Langmuir-film technique in this article, where exact control of refractive index and film thickness was achieved.
Abstract: Optical waveguiding has been demonstrated in planar Structures fabricated with long-chain organic molecules deposited by the Langmuir-film technique. Precise control of refractive index and film thickness was achieved. Attenuation losses are reported.
TL;DR: In this paper, a simple but rigorous transformation is introduced, which converts the anisotropic electrostatic field into an isotropic one with similar shape; the latter has been extensively analysed in the past.
Abstract: For the TEM-mode investigation of microstrip lines on anisotropic substrates, a simple, but rigorous, transformation is introduced, which converts the anisotropic electrostatic field into an isotropic one with similar shape; the latter has been extensively analysed in the past. The transformation also applies to related anisotropic problems. Results for single and coupled lines are presented. Dispersion is briefly commented on.
TL;DR: In this paper, the activation energies for electron traps present in the channel of GaAs microwave field-effect transistors are determined using a fast and sensitive technique, which can be applied toward identification and elimination of the traps.
Abstract: Described is a rapid, sensitive technique for determining the activation energies for electron traps present in the channel of GaAs microwave field-effect transistors. The measurements can be made directly on the f.e.t.s. Taken together with systematic variation of growth procedures, the method can be applied toward identification and elimination of the traps.
TL;DR: Various methods for the implementation of number-theoretic transforms to a prime or prime-power modulus are proposed and the condition for the existence of transforms in an arbitrary ring is given.
Abstract: We propose various methods for the implementation of number-theoretic transforms to a prime or prime-power modulus. Such transforms may be performed in a processor or by special hardware. We also give, without proof, the condition for the existence of transforms in an arbitrary ring.
TL;DR: In this paper, the eigenmodes of an inhomogeneous, anisotropic optical waveguide with arbitrary cross-section are computed using the finite element technique, based on a variational principle for the modes of a dielectric waveguide.
Abstract: Using the finite-element technique, the eigenmodes propagating in an inhomogeneous, anisotropic optical waveguide with arbitrary cross-section are computed The method is based on a variational principle for the modes of an anisotropic dielectric waveguide It is shown that very accurate results are obtained, even for the guides formed by very small changes in the refractive index As an example, the propagation characteristics of a channel guide embedded in LiNbO3 are computed
TL;DR: In this paper, an optical-fibre switch is described which depends on transverse mechanical motion of found fibres within a square-bore tube and the theoretical loss of the switch, when closed, can be as low as 0.05 dB and many tens of decibels when open.
Abstract: An optical-fibre switch is described which depends on transverse mechanical motion of found fibres within a square-bore tube. The theoretical loss of the switch, when closed, can be as low as 0.05 dB and many tens of decibels when open.
TL;DR: In this paper, the frequency spectra of impulsed transducers using PVF2 piezoelectric plastics films, combining efficient transduction with extremely wide and uniform passbands, have been fabricated without any critical tolerances.
Abstract: : Broadband ultrasonic transducers using PVF2 piezoelectric plastics films, combining efficient transduction with extremely wide and uniform passbands, have been fabricated using very simple procedures without any critical tolerances. Frequency spectra of impulsed transducers using films of 25 and 50 micron thickness, centered at 10 and 5 MHz, respectively, are shown.
TL;DR: In this article, the inductor-capacitor hybrid described by Reeves is analyzed by a lumped-circuit model, in which the metal foils in the device have finite resistance.
Abstract: The inductor-capacitor hybrid described by Reeves is analysed by a lumped-circuit model, in which the metal foils in the device have finite resistance. The earlier theory appears as a special case of the model, and some difficulties at the principal resonance are removed.