bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical Activity of Ferroelectric 5PbO·3GeO2 Single Crystals
Authors: Iwasaki Hiroshi , Sugii Kiyomasa
Published: January 2004

Optical rotatory power (ρ = ± 5°35′/mm for λ = 6328 Å) was found in the Czochralski-grown ferroelectric crystal 5PbO·3GeO2. Reversal of the ferroelectric spontaneous polarization Ps caused the enantiomorphic transformation of the crystal and consequently the change in the sign of the optical rotatory power. The gyration coefficient g33 was found to fit the equation g33 = γ33Ps, where γ33 is the electrogyration tensor in the paraelectric phase.
Cylindrical Magnetic Domain Epitaxial Films with Low Defect Density
Authors: Geusic J.E. , Levinstein H.J. , Licht S.J. , Shick L.K. , Brandle C.D.
Published: January 2004

Liquid-phase epitaxial, Er2Eu1Ga0.7Fe4.3O12, films have been grown on 〈111〉 Gd3Ga5O12 substrates with a magnetic-defect density as low as 2 defect/cm2.
Cylindrical Magnetic Domain Epitaxial Film Characterization: Device and Growth Implications
Authors: Hagedorn F.B. , Tabor W.J. , Geusic J.E. , Levinstein H.J. , Licht S.J. , Shick L.K.
Published: January 2004

The effects of magnetic material parameter variations on the operating bias-field and bubble diameter ranges of magnetic bubble devices are discussed theoretically. In addition, experimental measurements are reported of spatial variations observed in liquid-phase epitaxial garnet films of nominal composition Er2Eu1Ga0.7Fe4.3O12. Data are given for a film whose thickness was constant to ± 2.5% over an area of 0.6 cm2.
Efficient Electroluminescence from Zinc-Diffused Ga1−xAlxAs Diodes at 25°C
Authors: Dierschke E. G. , Stone L. E. , Haisty R. W.
Published: January 2004

Efficient Ga1−xAlxAs light-emitting diodes with zinc-diffused junctions have been fabricated. External quantum efficiencies as high as 14% for near-infrared diodes (8150 Å) and 4% for visible red diodes (6950 Å) have been achieved at 25°C. The high efficiencies result from using a hemispherically shaped emitter with a composition profile which reduces internal bulk absorption.
Voltage-Induced Optical Waveguide
Authors: Channin D. J.
Published: January 2004

An optical waveguide based on electro-optic index changes in LiNbO3 has been constructed. Voltage and polarization dependence of the waveguide mode structure has been observed and is described qualitatively with a simple theory.
Gain and Spectral Characteristics of a cw HF/DF Chemical Laser
Authors: Glaze James A.
Published: January 2004

Gain and spectral characteristics of a transverse-flow cw laser utilizing hydrogen fluoride (HF) and deuterium fluoride (DF) as the active medium is reported. Gains up to 4.3%/cm for 2–1 P-branch transitions for HF and 2.4%/cm for 3–2 P-branch transitions for DF have been observed. Both dispersive and nondispersive cavity geometries have been utilized for gain and spectral measurements. A brief comparison between observed gain curves and those obtained from a simple Boltzmann model is made.
Absorption of Unshifted Scattered Light by a Molecular I2 Filter in Brillouin and Raman Scattering
Authors: Devlin G. E. , Davis J. L. , Chase L. , Geschwind S.
Published: January 2004

A simple molecular I2 vapor filter is described which can attenuate the unshifted scattered light in Brillouin and Raman scattering by greater than 108 with a background attenuation of less than 10, i.e., a discrimination ratio of > 107 : 1.
Laser Emission from He-Air-C2N2–(CO)
Authors: Brandelik J. E. , Barry J. D. , Boney W. E.
Published: January 2004

Laser emission from a He-air-C2N2–(CO) mixture has been measured in air from 5.0416 to 5.7566 μ. The P(J)v,v′ transitions in CO occurred from v = 5 : 4 to v = 15 : 14 with J = 9 – 17 nominally. Multiline power levels exceeded 2 W with over 2% efficiency. The CO molecules were produced by the discharge initiated chemical process C2N2 + O2 = 2CO + N2.
Vacancy Association of Defects in Annealed GaAs
Authors: Chang L. L. , Esaki L. , Tsu R.
Published: January 2004

Cathodoluminescence measurements were performed at 5 °K on GaAs annealed from 600 to 1100 °C under controlled arsenic vapor pressures. Various energy levels of defects were observed, and their association with Ga or As vacancies were determined from the pressure dependence. The defects associated with Ga vacancies were found to become increasingly important with increasing temperatures. Fast diffusing species such as copper can be ruled out as being responsible for the observed defects.
An Attempt to Reproduce the Schwarz-Hora Effect
Authors: Hadley R. , Lynch D. W. , Stanek E. , Rosauer E. A.
Published: January 2004

Several attempts were made to observe the modulation of an electron beam by a laser (the Schwarz-Hora effect). These were not successful and possible reasons are reported.
Detection of Surface-Wave Three-Phonon Interaction
Authors: Tanski William J. , Mayer Walter G.
Published: January 2004

The resultant surface phonon generated by the interaction of two noncollinear surface phonons has been detected on the (111) face of a single-crystal copper sample. Detection was accomplished by optical probing of the two primary surface waves and the resultant phonons generated in the interaction.
Periodic Current and Radiation Pulsing in dc Excited Xenon Plasma
Authors: Chuang Shih-Shung , Gamo Hideya
Published: January 2004

A periodic current pulse with pulse width around 1.5 μsec and peak current around 1 A is generated in the dc excited pure xenon plasma when the capacitance between cathode and anode is increased. Each current pulse is accompanied by one or two supperradiant radiation pulses of 3.5-μm wavelength with pulse width ranging from 0.3 to 1 μsec and peak power of about 1 mW.
Independent Grain Behavior of Parametrically Excited π/2 Magnons in Polycrystalline YIG
Authors: Borghese Camillo , Roveda Riccardo
Published: January 2004

Longitudinal imaginary susceptibilities ∥χ″ in the spin-wave instability region were measured in YIG samples having bimodally distributed grain sizes. The samples were prepared by hot pressing mixtures of powders having grain sizes x of 1 and 10 μ. Two threshold fields exist for such samples: the low and high one, respectively, due to the coarse and fine grains. Two saturation levels are found for ∥χ″, approximately proportional to the respective volume fractions of fine and coarse grains. An expression for continuously x-distributed polycrystals is worked out on the basis of the single grain scattering mechanism, which compares favorably to experimental results.
Preswitching Behavior of Oxidized Vanadium Foils
Authors: Yu R. J. , Fisher P. D.
Published: January 2004

The results of an investigation into the preswitching behavior of oxidized vanadium foils are reported. The critical field required to actuate switching from the low-conductance state to the high-conductance state for various bath temperatures was measured along with the switching delay time as a function of applied field. The thermal transport equation was solved subject to the appropriate boundary conditions; expressions for the critical field and delay time were obtained and compared with experimental results.
Transient Effects in the Mode Locking of Nd3+-Glass Lasers
Authors: Wang Charles C. , Davis L.I.
Published: January 2004

It is proposed that limitations in the pulse width obtainable from ``mode-locked'' Nd3+-glass lasers result from the generation of only a limited number of side bands for each of the lasing frequencies. Experimental results in support of this model are discussed.
Megawatt Tunable Second Harmonic and Sum Frequency Generation at 280 nm from a Dye Laser
Authors: Bradley D.J. , Nicholas J.V. , Shaw J.R.D.
Published: January 2004

The second harmonic frequency of a high-power interferometrically narrowed and tuned rhodamine 6G dye laser has been generated in an ADP crystal with 10% efficiency. Twenty-millijoule-megawatt pulses, continuously wavelength tunable from 280 to 290 nm, have been obtained with a bandwidth of 0.2 nm. Ultraviolet sum frequencies have also been generated with similar efficiency.
Pressure-Dependent Absorption in BCl3 at 10.6 μ
Authors: Lavigne Pierre , Lachambre J.L.
Published: January 2004

The absorption of 26 lines of a CO2 laser by BCl3 has been measured over a wide range of pressures. At low pressures, saturation effects occurred for powers as low as 200 mW cm−2. Above 1 Torr, the absorption coefficient is found to increase linearly with pressure. A theoretical model, taking the effects of saturation and line overlapping into account, has been formulated to interpret these results.
Nuclear Spin-Lattice Relaxation in a Liquid Crystal Ordered in ac Electric Fields
Authors: Tarr C.E. , Fuller A.M. , Nickerson M.A.
Published: January 2004

The proton spin-lattice relaxation time T1 of p-methoxybenzilidene-p-n-butylaniline ordered in ac electric fields is reported. The second moment of the resonance line shape was used to determine the degree of alignment and orientation of the molecular axes with respect to the magnetic field. Evidence is shown for contributions to the relaxation processes from electric-field-induced turbulence.
Experimental Evidence for Elliptic Particle Motion Accompanied by Elastic Surface Waves
Authors: Kajimura Koji , Inaba Ritsuo , Mikoshiba Nobuo
Published: January 2004

Experimental evidence is given for the elliptic backward rotation of particles at the surface of a y-cut quartz on which elastic surface waves propagate along the x axis. The path of the particle motion is determined by the analysis of the electromotive force induced in a metal-strip detector in a static magnetic field. The experimental result on the ratio of the major and minor axes of the ellipse is in good agreement with a numerical calculation. The direct measurement of the particle displacement enables one to estimate the power of surface waves. The experiment suggests a possible application of elastic surface waves to a phase shifter in the range of VHF and UHF.
Thin-Film Optical-Waveguide Mode Converters Using Gyrotropic and Anisotropic Substrates
Authors: Wang Shyh , Crow John D. , Shah Manhar
Published: January 2004

Here we report a computer study of mode conversion in thin-film optical waveguides using gyrotropic YIG or anisotropic LiNbO3 as the substrate material. The computational results confirm that complete mode conversion from TE to TM or vice versa can be achieved if the mode converter is operated degenerately for both the TE and TM modes. Further, the length of the optical waveguide and the tolerances on the incident angle and film thickness indicate that the device is feasible.
A Variable Gain Laser Amplifier at 3.39 μ
Authors: Stone F.T. , Bresman J.M.
Published: January 2004

A variable gain laser amplifier has been tested that appears capable of operating over a wide range of gain values. The gain is controlled by placing the amplifier in a Fabry-Perot cavity and allowing it to oscillate. Small changes in amplifier cavity length produce large variations in the amplifier gain. Measured gain variations of 20 : 1 have been observed.
Linewidth of the Radiation Emitted by a Josephson Point Contact
Authors: Vernet G. , Adde R.
Published: January 2004

The emission linewidth of a Nb–Nb Josephson point contact is measured vs dc current and compared with the theoretical predictions of Stephen and Scalapino. The good agreement between experimental results and theory even for high junction currents, the pair current being generally much larger than the quasiparticle current, indicates that Stephen's theory gives a fair picture of the pair-current noise properties in point-contact junctions.
Comparative Study of Plasma Anodization of Silicon in a Column of a dc Glow Discharge
Authors: Copeland M. A. , Pappu R.
Published: January 2004

A comparative study of plasma anodization of silicon in the column of a dc oxygen glow discharge is presented. Quantitative results for growth rates of silicon dioxide in the negative glow, Faraday dark space, positive column, and the anode fall are given. It is observed that the growth rate is higher in the positive column than the other regions of the discharge.
Measurements of the Field Effect in Amorphous Switching Materials
Authors: Egerton R. F.
Published: January 2004

Conductivity modulation was observed in thin films of chalcogenide glass by applying an electric field through the (mica or plastic) substrate. At room temperature, the surface potential could be varied through ± 3kT, the surface being always p type, in agreement with the Seebeck coefficient. Comparison of the field-effect curves with equilibrium space-charge theory suggests a bulk density of localized states in the range from 1019 to 2 × 1020 cm−3 eV−1 within ± 0.1 eV of the Fermi level.
Hologram Storage in Arsenic Trisulfide Thin Films
Authors: Keneman S. A.
Published: January 2004

This letter reports preliminary results of experiments involving the storage of high-efficiency holograms in evaporated thin films of arsenic trisulfide (As2S3). Both simple gratings and holograms of complex data masks have been recorded in the films by direct exposure with no subsequent processing. Diffraction efficiencies of up to 80% have been measured for two-beam gratings. Several possible mechanisms are suggested to explain the observed results.
Electrically Controllable Domains in Nematic Liquid Crystals
Authors: Greubel W. , Wolff U.
Published: January 2004

It is reported here that it was observed that in suitable nematic liquid crystals in very thin sandwich cells from the threshold of domain formation up to the highest practicable field strength, the inverse domain width is proportional to the applied dc electric field, while dynamic scattering does not occur. Since such a cell performs as an electrically controllable optical grating which can be made to have very high diffraction efficiency, this effect may also be of practical interest.
Transparent Phase Images in Photoactivated Liquid Crystals
Authors: Margerum J. D. , Beard T. D. , Bleha W. P. , Wong S. -Y.
Published: January 2004

Photoactivated electric field effects in nematic liquid crystals serve as reversible nearly real-time techniques for recording phase-type holograms. In a sandwich-type cell, a photoconductive coating separates one conductive electrode from the liquid-crystal layer, which is operated below the threshold voltage for dynamic scattering. In CdS cells, transient first-order diffraction efficiencies of 10–30% are obtained within 0.1–0.2 sec from visible light exposures of less than 1 μJ/cm2. A 10-μW/cm2 Ar-ion laser interference pattern of 40 cycle/mm produced a steady-state first-order diffraction efficiency of 8% in a 13-μm thickness of MBBA in a cell operated at 4-V dc. Resolutions up to 100 cycle/mm are observed for this thickness of liquid crystal.
Carrier Profile Change for Phosphorus-Diffused Layers on Low-Temperature Heat Treatment
Authors: Schwettmann F. N. , Kendall D. L.
Published: January 2004

The low-temperature annealing of phosphorus-diffused layers in silicon is described. The sheet resistance of the diffused layer is found to increase with time at temperatures of 450–800°C. Carrier profiles for slices which have reached an equilibrium value of sheet resistance indicate a substantial decrease in the surface concentration. An Arrhenius plot of this concentration gives a straight line with an activation energy of 0.33 eV. In addition to a decrease in surface concentration, anomalously fast diffusion near the junction causes a significant tail on the profile. A model is presented to account for these results.
Growth of In2Bi Whiskers
Authors: Huckle J. R. , Davis J. H. , Lal R. B.
Published: January 2004

The first compound whisker grown by squeeze technique (In2Bi) is reported. Rotating crystal x-ray analysis and melting-point measurements confirmed that the whiskers were In2Bi. The whisker axis coincided with the 〈001〉 direction for all four whiskers. A scanning electron microscope photograph indicates that the whiskers have diameters of a few μ and a morphology similar to tin whiskers.
Electric Field Induced Memory Switching in Thin Films of the Chalcogenide System Ge–As–Se
Authors: Pinto R. , Ramanathan K. V.
Published: January 2004

A bistable switching has been observed in amorphous films of semiconducting glasses in the system Ge–As–Se in the thickness range 0.3–3 μm. The absence of a heat-induced devitrification and energy production considerations for switching showed that Joule heat produced while switching plays only a minor role in these glasses. Hence, the observed memory action has been attributed to an electric field induced phase transition along a filamentary path in the glass film.
Microwave-Biased Photoconductivity Experiments Using Microwave-Integrated-Circuit Techniques
Authors: Herczfeld P. R. , Dodson Don
Published: January 2004

Microwave-biased photoconductivity measurements on sulfur-sensitized CdS have been made using microwave-integrated-circuit transmission lines. Results are similar to those found using waveguide and show a difference in dc and microwave-biased photoconductivity.
Efficient Mode-Locked Frequency-Doubled Operation of an Nd:YAlO3 Laser
Authors: Rice R. R. , Burkhart G. H.
Published: January 2004

Narrow 0.540-μm second harmonic (SH) pulses (∼250 psec) have been observed from a mode-locked Nd:YAlO3 laser at a 300-mW SH power. The SH conversion efficiency observed was 50%. The laser was mode locked and frequency doubled using a single Ba2NaNb5O15 crystal, and emitted pulses at a frequency of c/l rather than c/2l at high conversion efficiencies. Since Nd:YAlO3 is transparent at 0.54 μm, complete extraction of the SH power generated in both directions is possible.
Low-Frequency Fluctuations of a GaAs Diode in the Relaxation Regime
Authors: Stoisiek M. , Wolf D. , Queisser H. J.
Published: January 2004

The reverse current of GaAs diodes fluctuates at frequencies between 2 and 10 Hz. In these diodes, the dielectric relaxation time τD exceeds the carrier lifetime τ0. This relaxation-case condition has been achieved by compensating oxygen doping. The fluctuation frequency depends on the applied voltage and on temperature. A thermal activation energy has been found corresponding to the energy of the oxygen impurities. The fluctuations can be explained by the slow motion of trapped charge packets which are injected under space-charge limitation.
An Electrically Excited Gas-Dynamic Carbon Monoxide Laser
Authors: Rich J. W. , Thompson H. M. , Treanor C. E. , Daiber J. W.
Published: January 2004

A carbon monoxide laser is reported which utilizes a glow discharge in the plenum of a supersonic nozzle. The discharge selectively excites the CO vibrational mode, while the gas translational temperature remains relatively cold. Continuous output is obtained from optical cavities established transverse to the flow at two nozzle area ratios. Maximum laser power obtained to date is 6.8 W corresponding to an efficiency of 0.6%, based on electrical power input.
Influence of Water on the Domain Structure of Epitaxy Films of Gadolinium Iron Garnet and Yttrium Iron Garnet
Authors: Lessoff H.
Published: January 2004

The effect of moisture on the magnetic domain patterns of single-crystal gadolinium iron garnet and yttrium iron garnet was observed. The change in magnetic domain structure and the disappearance of magnetic ``bubble'' domains is related to a reduction of surface stresses by water.
CdGeAs2—A New Nonlinear Crystal Phasematchable at 10.6 μm
Authors: Byer R. L. , Kildal H. , Feigelson R. S.
Published: January 2004

In this paper, we present the optical and nonlinear optical properties of a new nonlinear crystal CdGeAs2. The chalcopyrite structure (4̄2 m) crystal is positive birefringent with Δn equal to 0.1. It is phasematchable for second harmonic generation (SHG) and parametric interactions over most of its transparency range from 2.4 to 18 μm. In addition, it has the largest known nonlinear coefficient for a phasematchable crystal with the exception of tellurium. The measured nonlinear coefficient is 3.4 times GaAs. The calculated doubling efficiency for SHG of a CO2 laser is 10 times that of tellurium. The crystal promises to be a very useful nonlinear material for parametric interactions between 3 and 18 μm.
Novel Electro-Optical Storage Effect in a Certain Smectic Liquid Crystal
Authors: Tani C.
Published: January 2004

A novel electro-optical storage effect has been found in a certain smectic liquid crystal. The optical transmission of a smectic liquid film changes with the application of a dc or an ac exciting voltage and remains in the excited state after the field is removed. Some different effects are observed in a thin (12-μ) and a thick (100-μ) sample. The optical contrast ratios of a thin sample are about 10 : 1. The decay of the optical storage effect is a few percent in a week at 42 °C. V–I characteristics of the samples exhibit negative resistance which seems to suggest the change of the molecular state induced by electric fields.
Circuit Controlled Current Instabilities in ``S-Shaped'' Negative Differential Conductivity Elements
Authors: Shaw M. P. , Gastman I. J.
Published: January 2004

We compare the results of our theoretical analysis of an ``S-shaped'' negative differential conductivity (NDC) element in a circuit containing a capacitor in parallel with the NDC element in series with an inductor, with the results of our experiments on PNPN and Ovonic diodes. All the major features of the experimental results are accounted for by the theory. These include, for the PNPN diode, switching to stable points in the DNC region and the appearance of damped chirps in response to a voltage ramp; for the Ovonic diode, voltage tunable relaxation oscillations. The theory provides a framework within which one can categorize and characterize the various modes of behavior observed in all S-shaped NDC elements.
Nonlinear Optical Response of Conduction Electrons in a Superlattice
Authors: Tsu R. , Esaki L.
Published: January 2004

The nonlinear optical response of conduction electrons in a one-dimensional superlattice has been examined theoretically. Our results indicate that such structure may be a promising medium for nonlinear mixing of photons.
Stimulated Emission Involving the Nitrogen Isoelectronic Trap in GaAs1−xPx
Authors: Holonyak N. , Scifres D. R. , Burnham R. D. , Craford M. G. , Groves W. O. , Herzog A. H.
Published: January 2004

Earlier work on III–V semiconductor lasers has shown that stimulated emission occurs on band-to-band transitions or via transitions involving donors or acceptors. Based on the behavior of the N isoelectronic trap in promoting efficient carrier recombination in GaP, the present work shows that the N isoelectronic trap in GaAs1−xPx is distinct and over part of the composition range x it can be operated in recombination in the stimulated emission (laser) regime, thus establishing a fundamental new laser transition in a III−V semiconductor. These results (4.2 and 77°K) are obtained by means of optical pumping of lightly doped n-type samples of estimated high nitrogen concentration.
Stimulated Emission in an Indirect Semiconductor: N Isoelectronic Trap-Assisted Recombination in GaAs1−xPx (x > 0.44)
Authors: Holonyak N. , Scifres D. R. , Craford M. G. , Groves W. O. , Keune D. L.
Published: January 2004

Due to the short-range nature of the N isoelectronic trap potential in GaAs1−xPx and the favorable band structure of this III–V compound, strong recombination radiation can be excited on either side of the direct-indirect transition (x=0.44, 77°K). By means of cw excitation with an argon-ion laser, stimulated emission is demonstrated at 77°K in N-doped indirect GaAs1−xPx (x=0.50) operating on NN pair recombination transitions.
A Mode-Locked cw Dye Laser
Authors: Dienes A. , Ippen E. P. , Shank C. V.
Published: January 2004

The operation of a mode-locked cw dye laser is described. A stable output of repetitive 55-psec pulses has been obtained with an acousto-optic loss modulator in the dye-laser cavity. Pulse widths have been determined by autocorrelation measurements using second harmonic generation in ADP.
Explosion-Pumped Gas-Dynamic CO2 Laser
Authors: Tulip J. , Seguin H.
Published: January 2004

A gas-dynamic CO2 laser, in which the reservoir condition is achieved using an explosion, is described. Pulse energies of several joules have been obtained using common hydrocarbon fuels, including propane and natural gas.
Structure of Moving Domain Walls in Magnetic Materials
Authors: Schlömann Ernst
Published: January 2004

It is shown that in the regions far away from the center of a moving domain wall the distribution of magnetization is the same as in a spin wave of complex wave number. The structure of the moving wall is calculated rigorously for wall velocities v smaller than a certain critical velocity v1. At the critical velocity the derivative of the wall energy with respect to v becomes infinite. The wall mobility in the subcritical region (v < v1) is inversely proportional to the wall energy.
Observation of Xerographic Electrostatic Latent Images with a Scanning Electron Microscope
Authors: Fritz G. F. , Hoesterey D. C. , Brady L. E.
Published: January 2004

Xerographic latent images produced by the optical exposure of electrostatically charged photoconductive films have been studied with a scanning electron microscope. This technique provides a tool for studying the structure of the latent image independently of the development process.
Enhancement of Piezoelectric Surface-Wave Coupling by Thin-Film Perturbation
Authors: Reeder T. M. , Kino G. S. , Adams P. L.
Published: January 2004

Experimental measurements of interdigital transducer input impedance are used to demonstrate that the coupling constant for piezoelectric surface waves can be enhanced by the use of an appropriate thickness dielectric overlay film. Measurements of the SiO2/YZ lithium niobate configuration are described and compared with an exact calculation and a qualitative perturbation analysis.
Barrier Inhomogeneities on a Si–SiO2 Interface by Scanning Internal Photoemission
Authors: DiStefano T. H.
Published: January 2004

Scanning internal photoemission has been used to map barrier inhomogeneities in a sodium-contaminated Si–SiO2 interface. The interface barrier is lowered in local regions at which sodium accumulates.
Optical Levitation by Radiation Pressure
Authors: Ashkin A. , Dziedzic J. M.
Published: January 2004

The stable levitation of small transparent glass spheres by the forces of radiation pressure has been demonstrated experimentally in air and vacuum down to pressures ∼1 Torr. A single vertically directed focused TEM00-mode cw laser beam of ∼250 mW is sufficient to support stably a ∼20-μ glass sphere. The restoring forces acting on a particle trapped in an optical potential well were probed optically by a second laser beam. At low pressures, effects arising from residual radiometric forces were seen. Possible applications are mentioned.
Effect of Redundant Microstructure on Electromigration-Induced Failure
Authors: Learn Arthur J.
Published: January 2004

Aluminum films with grain boundaries staggered throughout the film thickness, and hence with nonoverlapping sites for electromigration-induced failure, were prepared by vacuum deposition in layered or extremely fine-grained form. Mean lifetimes before the occurrence of electrical opens were an order of magnitude larger than those for control films having non-redundant grain structure. Heat-treatment effects which reduced lifetimes to values comparable to control lifetimes were interpreted in terms of either a lifetime minimum for grain size ∼ 0.6 μ or disruption of the layered structure.
Semiconducting Properties of Cs2ZrCl6 and Cs2HfCl6
Authors: Tzalmona A. , Kaplan Z. , Gabay A.
Published: January 2004

It has been established that heat treatment in cesium vapor can convert the insulating Cs2ZrCl6 and Cs2HfCl6 crystals to semiconductors.
Optical Gain in Lightly Doped GaAs
Authors: Shaklee K. L. , Leheny R. F. , Nahory R. E.
Published: January 2004

Measurements of both small-signal gain and stimulated emission spectra for optically pumped GaAs are described. Saturation of the amplification process is shown to play an important role in determining the spectral distribution of the stimulated emission. These measurements indicate that intrinsic gain in high-purity material does not result from band-to-band recombination and in its place an interpretation in terms of free-exciton radiative Auger recombination is suggested.
Superconducting Properties of Niobium Carbonitride Thin Films
Authors: Gavaler J. R. , Janocko M. A. , Jones C. K.
Published: January 2004

A method for preparing thin films of nominal composition NbC0.3N0.7 is reported. Maximum transition temperatures of 17.3 °K are obtained for films deposited at ∼700 °C. However, higher critical currents and critical fields are obtained for films prepared at lower temperatures, even though the Tc's are lower. This effect is attributed to structural differences in the two types of films.
Punchthrough and the Tunneling Cryotron
Authors: Fulton T. A.
Published: January 2004

The effect of junction capacitance on the behavior of the Josephson tunneling cryotron is considered and certain problems which may arise in high-speed applications are described.
Radiation Effects Produced by Modulated Electrons
Authors: Lipkin H. J. , Peshkin M.
Published: January 2004

In the experiment of Schwarz and Hora, modulated electrons can radiate substantially more light than unmodulated electrons only if the modulated electron wave function contains many plane-wave components. The radiated light must be coherent if it is emitted from a one-electron state or collectively from a product of modulated one-electron states. These conclusions are independent of the mechanisms of excitation and radiation.
Auger Electron Spectroscopy in the Scanning Electron Microscope: Auger Electron Images
Authors: MacDonald N. C. , Waldrop J. R.
Published: January 2004

A two-dimensional surface chemical analysis over an area on a metal specimen has been accomplished by means of high-spatial-resolution Auger electron spectroscopy in a computerized scanning electron microscope. The experimental results are presented in graphic form by the new method of Auger electron imaging.
Infrared Detection by Schottky Barriers in Epitaxial PbTe
Authors: Logothetis E. M. , Holloway H. , Varga A. J. , Wilkes E.
Published: January 2004

High-quality infrared detectors have been made from Pb Schottky barriers on epitaxial PbTe layers. At 77 °K these devices are limited by the 300 °K background at f/1.7 and attain Johnson noise-limited peak detectivities [Dλ*(5.5 μ m, 600, 1)] of 6×1011 cm Hz1/2W−1 with further reduction of the background. The diode quantum efficiencies reach 50–60%.
Generation of Far-Infrared Radiation by Picosecond Light Pulses in LiNbO3
Authors: Yang K. H. , Richards P. L. , Shen Y. R.
Published: January 2004

We have observed far-infrared radiation generated by picosecond pulses in LiNbO3 with several different phase-matching conditions. The output spectra, analyzed by a far-infrared Michelson interferometer and by a Fabry-Perot interferometer, agree well with theoretical calculations. The laser pulsewidth deduced from these measurements was about 2 psec in comparison with 5 psec obtained from two-photon fluorescence measurements.
Anomalies in the Solubility for Zn in AlxGa1−xAs
Authors: Campbell D. R. , Shih K. K.
Published: January 2004

A comparative study has been made of the solubilities of Zn in AlxGa1−xAs (0.20≤x≤0.37) and GaAs at 700 °C. The use of three diffusion sources (92% Ga-6% Zn-2% As, pure Zn, and ZnAs2) provided a range of a factor of 40 in the measured solubility in GaAs. It was found that the solubility in AlxGa1−xAs increased with x for x>0.20 and that at low As4 pressures the solubility in Al0.20Ga0.80As exceeded that in GaAs whereas the reverse was true at high pressures. These findings may indicate the existence of unusually high defect concentrations in AlxGa1−xAs.
Tunable Coherent Radiation Source in the 5-μ Region
Authors: Pidgeon C. R. , Lax B. , Aggarwal R. L. , Chase C. E. , Brown F.
Published: January 2004

A tunable coherent radiation source in the 5-μ region has been obtained by mixing a spin-flip Raman (SFR) laser with a 10.6-μ TEA laser. The sum frequency, tunable from 5.47 to 5.79 μ, is obtained by mixing the two beams in a crystal of tellurium oriented at the phase-match angle. Output peak powers of approximately a few watts are obtained in this wavelength range.
Turn-On Time Reduction and Contrast Enhancement in Matrix-Addressed Liquid-Crystal Light Valves
Authors: Wild Peter J. , Nehring Jürgen
Published: January 2004

A new method of response time reduction and contrast enhancement in matrix-addressed liquid-crystal light-valve arrays is described based on the effect that the threshold for hydrodynamic instability in certain nematic liquid crystals is increased by a superimposed electric field of sufficiently high frequency. The effect is discussed in terms of the Helfrich model.
High D* Pyroelectric Polyvinylfluoride Detectors
Authors: Phelan Robert J. , Mahler Robert J. , Cook Alan R.
Published: January 2004

Polyvinylfluoride plastic films exhibit a normalized detectivity, D* (500 K, 1, 1), of 3×108 cm Hz1/2/W. This value for the infrared-detector figure of merit is close to the highest available from other pyroelectric materials. A pyroelectric coefficient of 1 nC/cm2K was obtained from the optical response, and a material figure of merit of 1.3×10−9 C cm/J was determined.
Two-Dimensionally Scannable Electron-Beam-Pumped Laser
Authors: Packard J. R. , Tait W. C. , Dierssen G. H.
Published: January 2004

A two-dimensional scanning laser has been produced by scanning a pumping electron beam across the faces of various II–VI semiconductors. The laser beam emerges coaxial with the electron beam from the excited point on the crystal with a spot size about the same diameter (20 μm) as the electron beam.
Highly Uniform Alx Ga1−x As Double-Heterostructure Lasers and Their Characteristics at Room Temperature
Authors: Miller B. I. , Pinkas E. , Hayashi I. , Foy P. W. , Capik R.
Published: January 2004

Highly uniform double-heterostructure wafers were grown reproducibly by liquid-phase epitaxy. Thresholds and efficiencies lie within 5% for different lasers from a given wafer. Studies of the effect of dopants in the active region of lasers made from these uniform wafers showed clearly the dependence of gain and loss characteristics upon some doping parameters. External differential quantum efficiencies of 50% were obtained consistently. Peak pulse power of 6 W and cw power of 200 mW were achieved with Fabry-Perot diodes.
Reproducible Preparation of Homogeneous In1−xGaxP Mixed Crystals
Authors: Itoh Hiroyuki , Hara Katsuo , Tanaka Akira , Sukegawa Tokuzo
Published: January 2004

A solution-growth method was developed to obtain highly homogeneous In1−xGaxP mixed crystals. In this method, a GaP crystal was the source material which was placed in the high-temperature portion of the In solution. An In1−xGaxP mixed crystal of a controlled composition crystallized in the low-temperature portion of the solution. The temperature of the solution and the vapor pressure of phosphorous were maintained constant in order to obtain mixed crystals of a high homogeneity. An x-ray analysis showed that the mixed crystals thus prepared were uniform within 0.01-mole fraction.
A New Technique for the Elemental Analysis of Thin Surface Layers of Solids
Authors: Coburn J. W. , Kay Eric
Published: January 2004

It is shown that the combination of rf glow-discharge sputtering and mass spectrometry provides a very sensitive method for determining the composition of thin surface layers of solids. The sample is immersed in an rf sputtering glow discharge and a fraction of those sputtered atoms which are ionized in the discharge by Penning ionization are monitored with a quadrupole mass filter. 1011 sputtered atom/sec can readily be detected and considerable improvement in sensitivity can easily be anticipated. The sensitivity is comparable for all elements except He, Ne, and F and is independent of the matrix in which the species are contained; i.e., standards are not required. The matrix can be electrically insulating or conducting.
A New Resolution Criterion for Long-Wavelength Holograms
Authors: Dickinson John , Rinard George
Published: January 2004

A new resolution criterion is described which can be used in long-wavelength holographic systems. It is called the finest-fringe criterion.
Surface Chemical Analysis by Auger Electron Spectroscopy and Appearance Potential Spectroscopy: A Comparison
Authors: Tracy J. C.
Published: January 2004

By direct comparison it is shown that Auger electron spectroscopy (AES) is more sensitive than appearance potential spectroscopy (APS) for the detection of S, C, and O on a Ti film. Similar combined studies of a number of clean films reveal that APS is about equally sensitive to Cr, Ti, Fe, and Ni, but is unable to detect Cu, Ag, or GaAs under the present conditions. The sensitivity of AES to all these materials in bulk form is the same within a factor of 5.
Nondestructive Testing of Thin Films by Harmonic Generation of Dispersive Rayleigh Waves
Authors: Lean E. G. , Powell C. G.
Published: January 2004

A new and sensitive measurement technique of determining elastic properties of a thin film on a substrate based on harmonic generation of dispersive Rayleigh waves is demonstrated. The technique has a sensitivity of detecting a change of 0.001% in velocity due to the loading of the thin film. A damaged layer of about 20 Å on a mechanically polished LiNbO3 substrate is detectable.
Polarization Effects in Holography
Authors: Okayama Hiroshi , Emori Yasufumi
Published: January 2004

The polarization characteristics of phase holograms are obtained in various spatial frequencies. These characteristics are evaluated by measurements of the diffraction efficiencies for the reconstructing beam, whose electric vector is parallel and perpendicular to the plane containing the reference and object beams, respectively.
Growth of Uniaxial Magnetic Garnet Films by a Simplified Method of Chemical Vapor Deposition
Authors: Taylor R. C. , Sadagopan V.
Published: January 2004

Epitaxial films of gallium-substituted yttrium iron garnet displaying magnetic domains have been grown on gadolinium gallium garnet and mixed gadolinium dysprosium gallium garnet substrates. The films grown on Dy: GGG were crack-free. A chemical-vapor-deposition (CVD) system using metal source materials and a simplified geometry was developed. Investigations were made of several different types of growth which occurred and of the efficiency of HCl transport. Results of these studies, as well as magnetic properties of the films and a description of the CVD system and growth conditions, are presented.
Visible Stimulated Emission in Ternary Chalcopyrite Sulfides and Selenides
Authors: Shay J. L. , Tell B. , Kasper H. M.
Published: January 2004

We report the observation of stimulated emission in four I-III-VI2 chalcopyrite sulfides and selenides AgGaS2, CuGaS2, AgGaSe2, and CuInS2 spanning the visible spectrum from 4650 to 8200 Å. CuGaS2 and CuInS2 can readily be prepared p type, and p-n junctions have been formed in CuInS2.
Variations in Electrical Properties of Silicon Films on Sapphire Using the MOS Hall Technique
Authors: Ipri A. C.
Published: January 2004

An experimental technique is described for determining the electrical properties of thin semiconducting films as a function of distance from the surface. The method is applied to silicon on sapphire films nominally 1 μ thick and doped ``n'' type on the order of (2–6)×1016/cm3, and the variation in average mobility and carrier concentration with depth into the layer is determined.
In1−x Gax P:N Laser Operation (cw, 77°K) on the Nitrogen A-Line Transition in Indirect Crystals (x ≥ 0.74) and in Direct Crystals above the Fundamental Band Edge (x ≥ 0.71)
Authors: Holonyak N. , Scifres D. R. , Macksey H. M. , Dupuis R. D.
Published: January 2004

The laser operation (cw, 77°K) of In1−xGaxP on the nitrogen A-line transition in indirect crystals (x≥0.74) and in direct crystals above the fundamental band edge (x≤0.71) is reported (5450 and 5470 Å, respectively). Thin (1–5 μ) experimental samples are prepared from crystals grown from In solution by a modified Bridgman method. The crystals are doped with GaN or N from the quartz of the synthesis ampoule. The samples are mounted in a sandwich configuration with indium wetted onto a copper heat sink on one side and thin CdS (10–20 μ) and sapphire on the other side. The thin samples are volume excited in a tiny spot by an argon-ion laser focused through the sapphire window and the CdS spacer which, with the sample, forms a high-Q compound cavity.
Phonon and Polariton Modes in a Superlattice
Authors: Tsu R. , Jha Sudhanshu S.
Published: January 2004

Calculations of the dispersion of phonons and polaritons in a superlattice show that the frequencies of the phonon and polariton modes may be prescribed by proper design. These modes may be useful as Raman source and Reststrahlen filters.
Two-Photon Absorption and Photoconductivity in GaAs and InP
Authors: Lee C. C. , Fan H. Y.
Published: January 2004

Absorption and photoconductivity in GaAs and InP have been studied as functions of light intensity I up to 20 MW/cm2 at 1.06 μ. The two-photon-absorption coefficient is determined to be ≈ 0.3I cm−1 for n-GaAs and ≈ 0.2I cm−1 for n-InP. These values are much larger than that predicted by the existing theories. For the n-InP samples, the absorption by the two-photon-excited free carriers is found to be important, giving an absorption coefficient of ≈ 0.15I2 cm−1. From the photoconductivity measurements, the concentration and the absorption cross section of holes are determined.
Avalanche Breakdown and Associated Light Emission in Molecular Crystals
Authors: Hsu S. T.
Published: January 2004

High-field-induced breakdown associated with light emission in anthracene crystals has been observed. The color of the emitted light is light blue in the 4000–4500-Å spectral region. The breakdown is identified as avalanche breakdown. The emitted light is due to radiative electron-hole recombinations.
Nonlinear Optical Susceptibility of 5-Nitrouracil
Authors: Bergman J. G. , Crane G. R. , Levine B. F. , Bethea C. G.
Published: January 2004

Nonlinear optical measurements show 5-nitrouracil (5NU) to be phase matchable with a co-efficient approximately equal to that of lithium iodate [d36(5NU) = (1.0 ± 0.2)d33(LiIO3)]. The large optical nonlinearity is attributed to a highly acentric molecular distribution of non-σ-bonded electrons. Air-stable nonoptically damageable single crystals were grown from an aqueous solution. X-ray results show the material to crystallize in the orthorhombic space group P212121 containing four molecules per unit cell of dimensions a0 = 9.94 ± 0.03 Å, b0 = 10.30 ± 0.03 Å, and c0 = 5.47 ± 0.02 Å. The crystals are transparent from 1.5 to 0.5 μ.
Structure of a Laser-Channeled Gas-Embedded z Pinch
Authors: Tidman D. A.
Published: January 2004

The structure of a proposed several-megaamperes discharge created along a narrow filament of laser-produced ionization through a high-density deuterium-tritium gas mixture is discussed. This initiation technique provides a convenient method for creating long straight gas-embedded z pinches (or screw pinches if a Bz is included) which may be of thermo-nuclear interest.
Gain Saturation in High-Resistivity Si:B Photoconductors
Authors: Blouke M. M. , Williams R. L.
Published: January 2004

Detailed observation of the photoconductive gain saturation in high-resistivity Si:B samples is reported. The calculated saturated gain of 0.52 agrees well with the theoretical prediction of Gsat = ½. These measurements strongly suggest that this phenomenon is a general characteristic of all high-impedance extrinsic photoconductors.
Subtractive Microwave Holography and Its Application to Plasma Studies
Authors: Iizuka Keigo
Published: January 2004

A subtractive-microwave-holographic technique is described in this letter. This technique appears to be novel in that it displays only the difference of the two dissimilar microwave fields. The effect is achieved by making use of the phase reversal which occurs when a contact print is made of the microwave hologram. The technique was demonstrated by subtracting the microwave image of a coin from that of three coins. To show the practicability of the technique, it was applied to the diagnosis of a plasma discharge. The fact that this method can eliminate the masking effects scattered by the glass envelope and its supports is a substantial improvement over other microwave diagnostic tools.
Spectral Investigation of Light Reflected from a Laser-Produced Deuterium Plasma
Authors: Büchl K. , Eidmann K. , Salzmann H. , Sigel R.
Published: January 2004

Plasma is created from solid deuterium targets by neodymium laser irradiation. The reflected laser light is shifted by 2.5 Å towards longer wavelengths. This is interpreted as a Doppler shift of the laser light reflected at a layer moving in the direction of the incident radiation with a velocity of 3.5×106 cm sec−1.
Channeling of Phosphorous Ions in Silicon
Authors: Reddi V. G. K. , Sansbury J. D.
Published: January 2004

Profiles of channeled 31P ions over the energy range 30–600 keV have been measured in 〈100〉, 〈111〉, and 〈110〉 Si. The maximum range Rmax of the channeled ions is nearly the same for the 〈100〉 and 〈111〉 directions and is significantly greater for the 〈110〉 direction.
Reliable Operation of a Proustite Parametric Oscillator
Authors: Hanna D. C. , Luther-Davies B. , Rutt H. N. , Smith R. C.
Published: January 2004

An infrared parametric oscillator using proustite and pumped at 1.065 μm has been operated with peak output powers in the kilowatt range. No significant deterioration of output power was observed after several hours of running at 2 pps. Tuning from 1.82 to 2.56 μm was obtained, limited only by the reflectivity limits of the mirrors used. With careful design, DRO proustite oscillators covering the entire range 1.2–9.5 μm now appear feasible.
Electron-Emission Images on LiF After Exposure to Intense Laser Light
Authors: Bräunlich P.
Published: January 2004

The observation of thermally stimulated emission of low-energy electrons (TSEE) from LiF single crystals that had been subjected to intense pulses of light from a Nd-glass laser is reported. TSEE images of the surface are obtained with the aid of an array of Channeltron electron multipliers. Correlations between image features and laser surface damage have been discovered that suggest the utilization of the TSEE image technique for nondestructive testing of optical surfaces with respect to their laser surface-damage threshold.
Growth-Induced Magnetic Anisotropy in Epitaxial Garnet Films
Authors: Rosencwaig A. , Tabor W. J.
Published: January 2004

Using the models established for the growth-induced anistropy in flux-grown crystals and parameters determined from anisotropy measurements in bulk crystals, the anisotropy in epitaxial films is predicted. Comparison with experiment shows that the signs of the anisotropy are correctly predicted and that magnitudes are in fair agreement.
Optically Erasable and Rewritable Solid-State Holograms
Authors: Gaylord T. K. , Rabson T.A. , Tittel F. K.
Published: January 2004

Optical holographic storage in single-crystal LiNbO3 is described which can be optically erased at room temperature and then rewritten with no degradation in efficiency or writing rate. The diffraction efficiencies associated with this process are about 10−4. Some variations from previously reported results include a lack of a threshold power density for writing, very-long-term persistence of the stored hologram, and a lack of a dependence of the diffracted intensity on the polarization of the readout beam.
A New Ferroelectric: Semicarbazide Hydrochloride
Authors: Rocaries J.-C. , Boldrini P.
Published: January 2004

Dielectric measurements on a single crystal of semicarbazide hydrochloride show three maxima at temperatures of −230, 19, and 21 °C. Initial data for the highest peak clearly suggest a ferroelectric-paraelectric transition with a Curie temperature of 21 °C. In the paraelectric region the Curie law is well followed.