Showing papers by "Alcatel-Lucent published in 1986"

Antiresonant reflecting optical waveguides in SiO2‐Si multilayer structures

Abstract: A new type of optical waveguide utilizing an antiresonant reflector is described. Implementation in the SiO2‐Si system gave losses as low as 0.4 dB/cm for the TE mode. The TM mode loss is >60 dB/cm, making the device an excellent planar technology integrated optic polarizer.

Effect of nonlinear gain reduction on semiconductor laser wavelength chirping

Abstract: A simple wavelength chirping formula is presented which includes small nonlinearities in the net gain such as spectral hole burning. The two dominant terms are a laser‐structure‐independent derivative or ‘‘transient’’ chirp and a structure‐dependent ‘‘adiabatic’’ chirp, each with distinctly different lightwave system consequences. The two chirp contributions are indirectly related through their mutual association with relaxation oscillations. Time‐resolved spectral measurements on a number of different laser structures support the results.

Redox capacity and direct current electron conductivity in electroactive materials

Abstract: Donnees obtenues pour le poly [Os(bpy) 2 (vpy 2 ] (ClO 4 ) x (x=0-3, bpy=bipyridine-2,2' et vpy=vinyl-4 pyridine)

Micrometer-spaced platinum interdigitated array electrode: fabrication, theory, and initial use

Abstract: : An interdigitated array (IDA) electrode composed of 40 pairs of 0.3 micrometers thick Pt fingers 3.5 micrometers wide and separated by 2.5 micrometer gaps of insulating borosilicate glass substrate has been fashioned by a modified microlithographic technique. The two IDA is applied to measurement of redox electron conduction through films of poly-Os(bpy)2 (vpy)2 (C1O4)2, poly-CRu(bpy)2 (vpy)2 (C104)2, and Prussian Blue that had been electrochemically deposited over the Pt fingers and in te insulating gaps. Appropriate theory for using the IDA for this purpose is developed. Electrochemically generated luminescence from solutions of Ru(bpy)3 (2+) is also observed with the IDA. (Author)

High quality Si‐on‐SiO2 films by large dose oxygen implantation and lamp annealing

Abstract: Ion beam synthesis of a buried SiO2 layer is an attractive silicon‐on‐insulator technology for high‐speed complementary metal‐oxide‐semiconductor circuits and radiation hardened devices. We demonstrate here a new annealing procedure at 1405 °C that produces silicon films of excellent quality, essentially free of oxygen precipitates and with sharp interfaces between the Si and the SiO2. Buried oxide layers have been formed in Si (100) wafers by implanting 400 keV molecular oxygen at 500 °C to a dose of 1.8×1018 cm−2. Annealing was performed by radiative heating of the back side of each sample to the melt temperature of silicon, TM=1412 °C, so that the buried oxide structure was at 1405 °C. The temperature control relies entirely on the change in optical properties of silicon upon melting. This ensures, without any external feedback, that the surface exposed to the photon flux will remain at TM.

Use of positrons to study transport in tokamak plasmas (invited)

Abstract: It now appears feasible to deposit positrons (e+) in a tokamak plasma by injecting bursts of neutral positronium atoms (e+e−), which are then ionized by the plasma The annihilation time of these positrons in the plasma is long compared with typical particle containment times Thus the subsequent transport of the positrons can be studied by monitoring the time dependence of the annihilation, gamma radiation produced when the positrons strike a limiter This paper discusses the design of such an experiment, the kinds of data which can be obtained, and the physics questions which this experiment might address This diagnostic technique could also be useful in studying transport in other magnetic confinement devices such as reversed‐field pinches and magnetic mirrors

Computer-controlled cordless telephone

Abstract: COMPUTER-CONTROLLED CORDLESS TELEPHONE Abstract A computer-controlled cordless telephone system having a base unit and a handset unit provides for increased functionality in communications between the base unit and the handset unit, and also provides a controlled power-up/power-down mode of operation for the handset unit. Increased functionality is achieved by employing a message format for control signals transmitted between the base unit and the handset unit in the form of frequency shift keyed (FSK) signals which include a data field. This data field may be in the form of either opcode data or digit data, thereby allowing for many different commands or functions. Power to a computer (10), a receiver (12) and certain other selected circuitry (11) in the handset unit is controlled to minimize power consumption when the handset unit is in an out-of-cradle-and-standby state. Power to other nonessential circuitry in the handset unit is turned completely off during this state. The handset unit automatically turns on to a full operating mode from the alternating power-up/power-down mode in response to events such as (1) a user depressing a key on the keypad (13) of the handset unit for either initiating a telephone call or paging the base unit, and (2) the base unit detecting an incoming ringing signal on the telephone lines.

Fast Phong shading

Abstract: Computer image generation systems often represent curved surfaces as a mesh of planar polygons that are shaded to restore a smooth appearance. Phong shading is a well known algorithm for producing a realistic shading but it has not been used by real-time systems because of the 3 additions, 1 division, and 1 square-root required per pixel for its evaluation. We describe a new formulation for Phong shading that reduces the amount of computation per pixel to only 2 additions for simple Lambertian reflection and 5 additions and 1 memory reference for Phong's complete reflection model. We also show how to extend our method to compute the specular component with the eye at a finite distance from the scene rather than at infinity as is usually assumed. The method can be implemented in hardware for real-time applications or in software to speed image generation for almost any system.

Testing in industrial experiments with ordered categorical data

Abstract: This article deals with some techniques for analyzing ordered categorical data from industrial experiments for quality improvement. Taguchi's accumulation analysis method is shown to have reasonable power fordetecting important location effects; however, it is an unnecessarily complicated procedure. For detecting dispersion effects, it need not even be as powerful as Pearson's chi-squared test. Instead two simple and easy to use scoring schemes are suggested for identifying the location and dispersion effects separately. The techniques are illustrated on data from an experiment to optimize the process of forming contact windows in complementary metal-oxide semiconductor circuits.

Self adjusting heaps

Abstract: In this paper we explore two themes in data structure design: amortized computational complexity and self adjustment. We are motivated by the following observations. In most applications of data structures, we wish to perform not just a single operation but a sequence of operations, possibly having correlated behavior. By averaging the running time per operation over a worst-case sequence of operations, we can sometimes obtain an overall time bound much smaller than the worst-case time per operation multiplied by the number of operations. We call this kind of averaging amortization.Standard kinds of data structures, such as the many varieties of balanced trees, are specifically designed so that the worst-case time per operation is small. Such efficiency is achieved by imposing an explicit structural constraint that must be maintained during updates, at a cost of both running time and storage space. However, if amortized running time is the complexity measure of interest, we can guarantee efficiency withou...

Ge-Si layered structures: Artificial crystals and complex cell ordered superlattices

Abstract: We report the first successful synthesis of ordered GeSi superlattices grown on (001) Si substrates by molecular beam epitaxy. Two types of structures were prepared and characterized: superlattices with one‐dimensional periodicity of one unit cell (GeGeSiSi...) and complex cell superlattices made up of sublayers of pure Si and alternating bilayers of Ge and Si. In the first case, the artificial stacking in the [001] direction results in a vertical array of alternating Ge and Si monolayers parallel to the (110) or (110) planes. In spite of the lattice mismatch of 4.2%, Rutherford backscattering and channeling experiments indicate high quality crystallinity in both types of structures. Long‐range order is deduced from the electron diffraction patterns that exhibit characteristic superlattice reflections and from high resolution lattice imaging. The precise deposition control on the scale of a fraction of a monolayer should allow band structure engineering in this and in other related systems and in turn ta...

Structural studies of the O6meG.C interaction in the d(C-G-C-G-A-A-T-T-C-O6meG-C-G) duplex.

Abstract: One- and two-dimensional nuclear magnetic resonance (NMR) experiments have been undertaken to investigate the conformation of the d(C1-G2-C3-G4-A5-A6-T7-T8-C9-O6meG10-C11-G12) self-complementary dodecanucleotide (henceforth called O6meG.C 12-mer), which contains C3.O6meG10 interactions in the interior of the helix. We observe intact base pairs at G2.C11 and G4.C9 on either side of the modification site at low temperature though these base pairs are kinetically destabilized in the O6meG.C 12-mer duplex compared to the G.C 12-mer duplex. One-dimensional nuclear Overhauser effects (NOEs) on the exchangeable imino protons demonstrate that the C3 and O6meG10 bases are stacked into the helix and act as spacers between the flanking G2.C11 and G4.C9 base pairs. The nonexchangeable base and H1', H2', H2'', H3', and H4' protons have been completely assigned in the O6meG.C 12-mer duplex at 25 degrees C by two-dimensional correlated (COSY) and nuclear Overhauser effect (NOESY) experiments. The observed NOEs and their directionality demonstrate that the O6meG.C 12-mer is a right-handed helix in which the O6meG10 and C3 bases maintain their anti conformation about the glycosidic bond at the modification site. The NOEs between the H8 of O6meG10 and the sugar protons of O6meG10 and adjacent C9 exhibit an altered pattern indicative of a small conformational change from a regular duplex in the C9-O6meG10 step of the O6meG.C 12-mer duplex. We propose a pairing scheme for the C3.O6meG10 interaction at the modification site. Three phosphorus resonances are shifted to low field of the normal spectral dispersion in the O6meG.C 12-mer phosphorus spectrum at low temperature, indicative of an altered phosphodiester backbone at the modification site. These NMR results are compared with the corresponding parameters in the G.C 12-mer, which contains Watson-Crick base pairs at the same position in the helix.

Observation of the triplet excited state of a conjugated-polymer crystal.

Abstract: By studying a single crystal of polydiacetylene-toluene-sulfonate, we have made the first identification of the triplet excited state of a conjugated polymer. The basis for this identification is the magnetic field dependence of the excited-state lifetime, which is measured by time-resolved optical absorption. Additionally, we have detected the Am = ±1 transitions between triplet sublevels by measuring microwave-induced changes in the triplet-state lifetime.

Zero-IF receiver wih feedback loop for suppressing interfering signals

Abstract: A working on the zero IF principle is disclosed which contains a feedback circuit instead of a preselector for suppressing interfering signals. The interfering signals contained in the incoming signal (F E ) are separated from the useful signal by filters in the baseband. They are then reconverted to the RF value, amplified, and substracted from the incoming signal (F E ) by a subtracter (S1). In the steady state, the output of the subtracter (S1) provides the useful signal, which is converted into the baseband and then fed to a signal processor (SV).

Diffusion-limited growth of wetting layers.

Abstract: In binary liquid mixtures, the growth of wetting layers can be limited by diffusion. At complete wetting, the distance i between the interfaces bounding the layer is shown to grow as i(t) = A «t' for large times t where A~ increases near the consolute point. In three dimensions where this growth behavior should be accessible to experiments, 8 = T and ~ for nonretarded and retarded van der %aals forces, respectively. The interfacial motion resulting from diffusion-limited growth is studied for general interactions, and a planar interface is found to be stable for 8 & ~.

Cytochrome c peroxidase compound ES is identical with horseradish peroxidase compound I in iron-ligand distances

Abstract: X-ray absorption studies of compound ES of cytochrome c peroxidase show a short iron-oxygen distance of 1.67 +/- 0.04 A, an iron-histamine distance of 1.91 +/- 0.03 A, and an iron-pyrrole nitrogen average distance of 2.02 +/- 0.02 A. This is identical within the error with the reported structure of horseradish peroxidase compound I [Chance, B., Powers, L., Ching, Y., Poulos, T., Yamazaki, I., & Paul, K. G. (1984) Arch. Biochem. Biophys. 235, 596-611]. Comparisons of the structures of myoglobin peroxide [Chance, M., Powers, L., Kumar, C., & Chance, B. (1986) Biochemistry (preceding paper in this issue)], compound ES, and the intermediates of horseradish peroxidase reveal the possible mechanisms for the stabilization of the free radical species generated during catalysis. The proximal histidine regulates the structure and function of the pyrrole nitrogens and the heme, allowing for the formation and maintenance of the characteristic intermediates.

Cabinet for an optical cable head

Abstract: The cabinet comprises a rear portion (1) fixed on the risers (15) of a rack, and a front portion (2) which is hinged to the rear portion. The rear portion (1) is fitted with means (27, 30-31, 28) for processing the component parts of a cable received by a cabinet to enable the component parts to be distributed out from the cabinet or else to be distributed in the form of individual fibers to the front portion of the cabinet, which front portion includes optical centering devices (60) for providing connections between the fibers received from the rear portion of the cabinet and link elements for providing links to opto-electronic equipment. Said optical centering devices are mounted in the front portion in such a manner as to ensure that they transmit light flux parallel to its front face. The cabinet is applicable to telecommunications stations.

X-ray absorption studies of myoglobin peroxide reveal functional differences between globins and heme enzymes.

Abstract: X-ray absorption studies of myoglobin peroxide show that although it is not identical with compound I or II of horseradish peroxidase [Chance, B., Powers, L., Ching, Y., Poulos, T., Yamazaki, I., & Paul, K. G. (1984) Arch. Biochem. Biophys. 235, 596-611], it has some structural features in common with both. As seen in compound I, the Fe-O distance is short, but the iron-pyrrole nitrogen distance is contracted with a longer iron-histidine distance like compound II. The iron has a higher oxidation state than Fe3+, suggesting an oxyferryl ion type species. Comparison of the structures of various peroxidase and myoglobin compounds points out systematic differences that may explain the catalytic activity of the pi cation radical as well as some of the differences between globins and heme enzymes.

Remote control system for franking machines

Abstract: A remote control system for a set of machines (1) for franking mail, which machines are geographically dispersed in accordance with user requirements and include franking heads whose use is monitored by a distant central organization. Each franking head is connected to a local concentrator station (4) via a data transmission link (11), and each local station is in turn connected via a telephone channel (3) to a central remote monitoring station (2) belonging the central organization. Each local station monitors the machines connected thereto and collects operating information supplied by their heads, and it interchanges data with the central station in differed time.

Reflow Mechanisms of Contact Vias in VLSI Processing

Abstract: During glass reflow of contact vias in VLSI processing, occurrences of a sidewall overhang (i.e., bulging and, as a result, formation of a reentrant angle at the base of a via) and, in extreme cases, closure of vias were observed when a low temperature flowing borophosphosilicate glass was used with closely spaced vias. A detailed consideration of the forces and mechanisms involved in reflow indicates that neither the chemical nature of the glass nor the specific processing parameters of reflow are factors in altering this phenomenon. Consideration of an idealized geometry shows that a sidewall overhang within vias will occur after reflow if the glass thickness is more than a critical fraction of the spacing between vias; this critical fraction is calculated to occur near a value of 0.4. At all glass thicknesses, a certain amount of overhang will develop at an intermediate stage of reflow, but then this overhang disappears for a subcritical glass thickness or grows for a supercritical glass thickness. In extreme cases, a large overhang can lead to spreading at the glass‐substrate interface, which contributes to closure of vias.

System for interconnecting orthogonally disposed printed circuit boards and switching networks employing same

Abstract: A system for interconnecting orthogonally disposed printed circuit boards in first and second stacks comprises first contact members on facing edges of the boards of the two stacks used to interconnect the boards. A mother board is disposed perpendicular to and between the two stacks of boards. Second contact members are disposed on the same facing edges of the boards as the first contact members. They define with the first contact members a series of first multiway plug-in connectors along the respective edge of each board in the first stack and a series of second multiway plug-in connectors along the respective edge of each board in the second stack. The mother board comprises a distribution network in the form of an array of conductive tracks assigned to distributing signals to the boards. The mother board also carries connecting contact members and distribution contact members connected to the distribution network. They are disposed transversely to the mother board and define on one side of it a set of third multiway plug-in connectors adapted to have the first connectors plugged into them. On the other side of the mother board they define a set of fourth multiway plug-in connectors adapted to have the second connectors plugged into them. These interconnect the first contact members of corresponding first and second connectors via the connecting contact members. They also connect the second contact members of each board to the distribution network via the distribution contact members.

Spontaneous organization of carboxylic acid monolayer films in ultrahigh vacuum. Kinetic constraints to assembly via gas-phase adsorption

Abstract: Resultats de l'etude de la chimisorption des acides carboxyliques en C 1 -C 4 et C 6 sur Cu(100) par spectroscopie de perte d'energie electronique et par spectrometrie de masse apres thermodesorption

Probabilistic analysis of optimum partitioning

Abstract: Given a set of n items with real-valued sizes, the optimum partition problem asks how it can be partitioned into two subsets so that the absolute value of the difference of the sums of the sizes over the two subsets is minimized. We present bounds on the probability distribution of this minimum under the assumption that the sizes are independent random variables drawn from a common distribution. For a large class of distributions, we determine the asymptotic behavior of the median of this minimum, and show that it is exponentially small.

Studies of anaerobic and aerobic glycolysis in Saccharomyces cerevisiae.

Abstract: Glucose metabolism was followed in suspensions of Saccharomyces cerevisiae by using 13C NMR and 14C radioactive labeling techniques and by Warburg manometer experiments. These experiments were performed for cells grown with various carbon sources in the growth medium, so as to evaluate the effect of catabolite repression. The rate of glucose utilization was most conveniently determined by the 13C NMR experiments, which measured the concentration of [1-13C]glucose, whereas the distribution of end products was determined from the 13C and the 14C experiments. By combining these measurements the flows into the various pathways that contribute to glucose catabolism were estimated, and the effect of oxygen upon glucose catabolism was evaluated. From these measurements, the Pasteur quotient (PQ) for glucose catabolism was calculated to be 2.95 for acetate-grown cells and 1.89 for cells grown on glucose into saturation. The Warburg experiments provided an independent estimate of glucose catabolism. The PQ estimated from Warburg experiments was 2.9 for acetate-grown cells in excellent agreement with the labeled carbon experiments and 4.6 for cells grown into saturation, which did not agree. Possible explanations of these differences are discussed. From these data an estimate is obtained of the net flow through the Embden-Meyerhof-Parnas pathway. The backward flow through fructose-1,6-bisphosphatase (Fru-1,6-P2-ase) was calculated from the "scrambling" of the 13C label of [1-13C]glucose into the C1 and C6 positions of trehalose. Combining these data allowed us to calculate the net flux through phosphofructokinase (PFK). For acetate-grown cells we found that the relative flow through PFK is a factor of 1.7 faster anaerobically than aerobically.(ABSTRACT TRUNCATED AT 250 WORDS)

A symmetric submicron CMOS technology

Abstract: A CMOS process is described that is designed to optimize the transistor characteristics of the n-channel and p-channel devices simultaneously. This is achieved by making the n- and p-channel devices symmetric in channel doping, junction depths, sheet resistivities and threshold voltages. The resulting devices have CoSi 2 source/drains with sheet resistivities of 1.5-2 Ω/square, n+ and p+ polysilicon/TaSi 2 gate structures, Threshold voltages of 0.4 V and 1.5 µm separation between active to tub-edge regions. Diode characteristics of the CoSi 2 /n+ and CoSi 2 /P+ are determined to be as good as non-silicided silicon junctions. Maintaining the proper doping for the connected n+ and p+ polysilicon/silicide gates is demonstrated. Ring oscillator delays of 110 ps at 3.5 V are observed for devices with 0.5 µm channel lengths. The ring oscillator circuits are still operational at power supply voltages of 1.0 V due to the low threshold voltage of the transistors.

Spin dynamics of nearly localized electrons.

Abstract: Etude RPE de Si:P metallique au voisinage de la transition metal-isolant, entre 100 K et 30 mK. Analyse des variations de la susceptibilite de spin paramagnetique et de la largeur de raie RPE en fonction de la temperature; relations avec l'amplification des fluctuations de spin et le ralentissement de la diffusion de spin au voisinage de la transition

Semiconductor analysis using organic-on-inorganic contact barriers. I. Theory of the effects of surface states on diode potential and ac admittance

Abstract: A new method for measuring the density of states at semiconductor surfaces using organic‐on‐inorganic (OI) semiconductor contact barriers is suggested. This work is an extension of previous models of OI diode behavior which includes the ac admittance characteristics, and which considers the range of validity of approximations to OI diode capacitance used in previous experiments. The theory describes the potential distribution across the device. We consider the case of ideal OI diodes, as well as diodes with significant densities of states at the inorganic semiconductor surface. This analysis leads to a technique whereby the low‐frequency conductance and capacitance characteristics can be used to obtain information about the magnitude and the energy distribution of surface states in the inorganic semiconductor bandgap. Also, the carrier concentration profiles of the substrate can be conveniently obtained. Due to the noninvasive nature of the organic/inorganic contact, information about the density of states at relatively undisturbed semiconductor surfaces obtained via this technique may prove useful in determining the processes involved in Schottky barrier formation and metal‐insulator‐semiconductor diode surface properties. This theory has been applied to the investigation of surfaces of III‐V alloy semiconductor‐based OI diodes, and the experimental results will be presented in a subsequent paper. In addition, an expression for the OI diode n value obtained from the forward current‐voltage characteristics is derived. It is found that the n value depends on surface states which are in equilibrium with the organic as well as the inorganic materials. Estimates of the surface state densities obtained from previously reported n values are consistent with expectations for the semiconductors under test.