bluuebunny/crossref_metadata_2025 huggingface dataset:
Particle arrival statistics in laser anemometry of turbulent flow
Authors: Erdmann J. C. , Gellert R. I.
Published: February 2003

Spectral information on turbulent fluid flow can be obtained from the rate statistics of tracer particles imbedded in the flow. In particular, the particle velocity correlation function can be measured by a laser technique with a single focused beam, which also provides a means to assess the lag behavior of the particles. The method offers significant simplifications of commonly used instrumentation.
Stimulated VUV emission from carbonlike ions in laser-produced plasmas
Authors: Davis J. , Whitney K. G.
Published: February 2003

Population inversion for transitions in the VUV are predicted theoretically in laser-produced plasmas. The calculations are based on a time-dependent model that treats the excitation, ionization, and recombination dynamics of a dense argon plasma. Gains in excess of 103 cm−1 are obtained for the 3s-3p transition in carbonlike argon XIII for over 1000 psec.
Backward Raman amplification and pulse steepening in silica fibers
Authors: Lin Chinlon , Stolen Rogers H.
Published: February 2003

Backward Raman amplification in a fused-silica fiber waveguide is studied using two dye lasers for its possible application as an amplifier and a pulse sharpening device. Greater than 90% of pump to signal conversion is observed together with a preferential amplification of the signal pulse front. Short pulse generation and complete pump depletion are also observed in a single dye laser pumped fiber Raman generator-amplifier system.
Electroluminescent p-InP/n-CdS heterodiodes
Authors: Wagner Sigurd , Shay J. L. , Bhar T. N. , Schiavone L. M. , Bachmann K. J. , Buehler E.
Published: February 2003

p-InP/n-CdS heterodiodes electroluminesce under forward bias. In diodes prepared by in vacuo growth of CdS layers on InP substrates, the spectrum is determined by recombination through deep interface states. Anneals at 500–600 °C shift the emission to energies close to the band gap of InP.
Carbon-ion-implanted gallium arsenide
Authors: Shin B. K.
Published: February 2003

Sheet-resistivity and Hall-effect measurements were made on C-ion-implanted GaAs after annealings at 600, 700, 800, or 900 °C. A doping efficiency of up to 50% was obtained in the 900 °C-annealed sample which is much higher than the 2–8% reported previously. The electrical profile of this sample indicated that most of the implanted C became substitutional. The electrical compensation level, on the other hand, remained relatively high (0.3–0.6) throughout the profiling range and is responsible for the low doping efficiency obtained in the C-implanted p-type GaAs.
Temperature noise and dielectric loss in pyroelectric detectors
Authors: Stokowski S. E.
Published: February 2003

It is shown theoretically and experimentally that the presence of thermal conductance between a pyroelectric material and its environment affects significantly its measured dielectric loss. Depending on the details of the heat exchange with the environment, this thermal contribution to the measured dielectric loss tangent can be larger than the intrinsic loss tangent of the material, i.e., loss due to domain wall motion, defects, and impurities. In detectors fabricated from LiTaO3, temperature fluctuations due to this thermal conductance, known as temperature noise, are observed to limit the normalized detectivity (D*).
Magnetic fields due to impurity grains in laser-produced plasma
Authors: Colombant D. G. , Tidman D. A. , Winsor N. K.
Published: February 2003

Results of a numerical simulation model are given for the magnetic field produced by an impurity grain embedded in a dense inhomogeneous plasma.
Effects of aging on thermally stimulated currents in poly(vinylidene fluoride)
Authors: Sharp E. J. , Garn L. E.
Published: February 2003

We have measured the total current [a sum of the thermally stimulated current (TSC) and the pyroelectric current] released as a function of temperature at a constant heating rate for numerous samples of poly(vinylidene fluoride) (PVF2) films which were poled in an electric field under a variety of conditions. An analysis of this data reveals significant changes in the TSC curves of room-temperature–poled PVF2 samples as a function of rest time after poling. The possible relaxation processes accounting for these changes are discussed. The pyroelectric response of these films has also been determined and a pyroelectric coefficient of 2.5×10−9 C/cm2 °K has been obtained for room-temperature–poled samples.
Nonpolymeric organic host for recording volume phase holograms
Authors: Bloom Allen , Bartolini R. A. , Hung P. L. K. , Ross D. L.
Published: February 2003

Sucrose benzoate has been used as a host for recording volume phase holograms. Diffraction efficiencies up to 75% are obtained using a variety of photosensitive guests. Fixed or self-erasing holgrams can be obtained.
Small-size discrete-capacitor N2 laser
Authors: Sam C. L.
Published: February 2003

This letter describes a small N2 laser using discrete capacitors in a Blumlein-type circuit with a 15-cm-long discharge length which yields 170-kW peak power in a 5.5-nsec pulse at 17-kV charging voltage. The high-power conversion efficiency of 0.065% attained is attributed to the low inductance of the circuit and the use of an external optical cavity.
Auger studies of Au diffusion through Pt films; dependence on annealing ambient
Authors: Chang C. C. , Quintana G.
Published: February 2003

Pt/Au thin-film couples were heat treated in 1 atm N2, He, and in vacuum. The outdiffusion kinetics of Au through the Pt were determined by measuring the Au concentration on the Pt surface using Auger electron spectroscopy. Au was found to outdiffuse through 6–10 kÅ Pt at rates 15 and 30 times faster in 1 atm N2 and 1 atm He, respectively, than in vacuum, at 350 °C. These results are the first published documentation of the remarkable acceleration of thin-film interdiffusion caused by the presence of nonreacting gases.
Total electron impact excitation cross sections of Ar and Kr
Authors: Jacob J. H. , Mangano J. A.
Published: February 2003

A simple accurate method for normalizing the absolute magnitude of measured relative rare-gas excitation cross-section data to published measurements of the first Townsend coefficient is presented. Using a code which solved the Boltzmann equation we have determined that the predicted first Townsend coefficient is a very sensitive function of the electron impact excitation cross section. In Ar and Kr we have found that a 10% change in the cross section results in a 30% change in the first Townsend coefficient.
Photoinduced disappearance and restoration of the fluorescence in rhodamine-6G–doped polyurethane film
Authors: Matsuda A. , Iizima S.
Published: February 2003

Photoinduced restoration of once-weakened fluorescence has been found in rhodamine-6G–doped polyurethane film. Formation and annihilation of the quencher of the fluorescence by the irradiation of laser light seems to be closely related to the disappearance and restoration of the fluorescence.
MIS solar cell—General theory and new experimental results for silicon
Authors: Green Martin A. , Godfrey R. B.
Published: February 2003

The metal–thin-insulator–semiconductor structure recently has been shown to have potential as a simple efficient solar cell. A general theory of these solar cells as well as experimental results for silicon devices optimized on the basis of this theory are described. The experimental devices have exceptionally good open-circuit voltages. Under illumination resulting in a short-circuit current density of 32 mA/cm2, an open-circuit voltage of 618 mV and a fill factor of 0.6 were obtained.
Energy gaps of ordered and disordered A15 ’’phases’’ in Nb3Ge measured by tunneling
Authors: Rowell J. M. , Schmidt P. H.
Published: February 2003

In electron tunneling measurements into high-Tc getter-sputtered Nb3Ge films, two energy gaps are clearly identified. The larger, 2Δ=7.8 meV, we associate with well-ordered A15 material. The smaller, 2Δ∼1.0 meV, we suggest indicates the presence of very disordered material, because we cannot identify any known phase of the NbGe system with this low gap, and because a most interesting ’’phase’’ of Nb3Ge, with 2Δ=0.86 meV and Tc=3.06 K, was isolated by sputtering from the same target onto a cold (100−200 °C) substrate.
Self-focusing parallel-plate waveguide CO2 laser with uniform transverse excitation
Authors: Nishihara H. , Mukai T. , Inoue T. , Koyama J.
Published: February 2003

A new type of waveguide CO2 laser with a previously proposed waveguide structure and a uniform transverse but horizontal (parallel to the waveguide surface) excitation is reported. The waveguide consists of a pair of slightly curved parallel plates which have a low-loss transmission and a self-focusing property; flat mirrors are set directly at both ends of the waveguide. The laser provides 30 W peak power at the repetition frequency of 3 kHz at pressures as high as 250 Torr. The output beam is 70% horizontally polarized, indicating laser oscillation mainly in the TE1 waveguide mode within the resonator.
Sources of oxidation-induced stacking faults in Czochralski silicon wafers
Authors: Rozgonyi G. A. , Mahajan S. , Read M. H. , Brasen D.
Published: February 2003

Using optical microscopy/etch pit techniques for the delineation of defects in {100} Czochralski silicon wafers we have made a one-to-one correlation between bulk stacking faults in oxidized wafers and etch hillocks identified at the same sites before oxidation. Transmission electron microscopy of the hillock defects shows them to be clusters of precipitates ranging in size from 0.01 to 0.3 μm. A discussion of these stacking-fault nucleation sites in light of previous work on ’’swirl’’ defects in float-zone wafers and attempts at preoxidation gettering are also presented along with a model for the formation of the extrinsic stacking faults.
High-power vibration-rotation emission from 14NH3 optically pumped off resonance
Authors: Danielewicz E. J. , Malk E. G. , Coleman P. D.
Published: February 2003

Off-resonance optical pumping of the sR (5,0) line of the ν2 fundamental band of 14NH3 has yielded over 2.0 kW of superfluorescent emission on the sP (7,0) transition at 12.079 μm. Emission at 11.460 μm attributed to the aP (3,1) transition was also observed by pumping the aR (1,1) absorption line with a 1-MW CO2 TEA laser.
KrF-laser-pumped tunable dye laser in the ultraviolet
Authors: Sutton D. G. , Capelle Gene A.
Published: February 2003

Tunable laser emission in the 335–346-nm region has been obtained from a 0.01M solution of p-terphenyl in p-dioxane. The dye laser was excited by a 20-nsec pulse from a Blumlein-driven KrF laser oscillating at 249 and 250 nm.
Background suppression in coherent Raman spectroscopy
Authors: Song J. J. , Eesley G. L. , Levenson M. D.
Published: February 2003

Background signals which appear in Coherent anti-Stokes Raman spectroscopy and in the Raman-induced Kerr effect can be eliminated using polarization technqiues based upon four-wave mixing. Specific polarization conditions will suppress all signals with the exception of those arising from Raman modes. The interference between resonant and background contributions is eliminated, and undistorted line shapes are obtained.
Arc suppression in CO2 laser discharges
Authors: Kline Laurence E. , Denes L. J. , Pechersky M. J.
Published: February 2003

We have parameterized the times to arc formation in CO2 : N2 : He mixtures using a TEA configuration which produces homogeneous 10-liter laser discharges. The onset of arcing is suppressed by increasing the helium or decreasing the CO2 concentration. Arcs are also suppressed by adding a low-ionization-potential seedant such as tripropylamine. Direct variation of the uv spark intensity which establishes the initial preionization has minimal impact on the arc formation process.
Arrival-time detection in drift mobility measurements using an interdigital electrode
Authors: Young Ralph H. , Mey William , Marchetti Alfred P.
Published: February 2003

The conventional (time-of-flight) technique for studying charge transport in a slab or film of photoconductive insulator monitors the average current density in the sample. An interdigital electrode can be used to monitor the current density near the surface of the sample, a more specific form of information. Illustrative results are presented for photogenerated electrons in azulene and in anthracene containing deep traps. Prospective applications are noted, particularly to the study of amorphous photoconductors.
Laser-produced-plasma energy transport through plastic films
Authors: Young F. C. , Whitlock R. R. , Decoste R. , Ripin B. H. , Nagel D. J. , Stamper J. A. , McMahon J. M. , Bodner S. E.
Published: February 2003

The transport of energy from a 1.06-μm, 95-psec laser pulse at an irradiance of 1015 W/cm2 through a thin layer of polystyrene into an Al substrate was studied by x-ray, ion, and scattered-light measurements. The intensities of the following quantities were measured as a function of polystyrene thickness: (1) x-ray line radiation from the Al backing, (2) bremsstrahlung continuum from 3 to 88 keV, (3) ions of several keV energy, and (4) scattered laser light. The results indicate that a polystyrene thickness of no more than 0.5 μm is sufficient to inhibit substantial heating of the Al substrate.
Anomalous photoresponse of n-TiO2 electrode in a photoelectrochemical cell
Authors: Morisaki H. , Hariya M. , Yazawa K.
Published: February 2003

The current-potential characteristics of n-TiO2 electrodes have been investigated in a photoelectrochemical cell. Photoresponse induced by the light of energy lower than the band gap of TiO2 has been observed in the potential range between −1.0 and −1.4 V vs SCE in 1N NaOH. The photoresponse, which is sensitive to the oxygen gas dissolved in solution, has been attributed to some surface states at the TiO2-electrolyte interface.
Nuclear-pumped lasing of 3He-Xe and 3He-Kr
Authors: De Young R. J. , Jalufka N. W. , Hohl F.
Published: February 2003

Direct nuclear pumping of 3He-Xe and 3He-Kr has been achieved using the volumetric 3He(n,p)3H nuclear reaction. Lasing occurred at 2.027 μ and near 2.5 μ in Xe I and Kr I, respectively. The Xe transition has the lowest lasing flux threshold to date, 4×1015 n/cm2 sec. Scaling with both thermal flux and total pressure has been investigated.
Integrated GaAs-AlxGa1−xAs injection lasers and detectors with etched reflectors
Authors: Merz J. L. , Logan R. A.
Published: February 2003

An integrated injection laser-waveguide-detector device is described, fabricated from AlxGa1−xAs layers grown by liquid-phase epitaxy. Reflectors are formed by a two-step preferential etch procedure. For a laser cavity formed by one etched reflector and one cleaved mirror, an overall differential transfer efficiency of 10±1% has been measured at the detector after transmission through a 1-μm-thick passive waveguide 250 μm long. If both reflectors are etched, efficiencies as high as 2% are still observed.
Self-aligned three-dimensional Ga1−xAlxAs structures grown by molecular beam epitaxy
Authors: Nagata Seiichi , Tanaka Tsuneo , Fukai Masakazu
Published: February 2003

Local thicknesses of a GaAs epitaxial layer grown on a mesa stripe by semiparallel Ga and As4 molecular beams have been found to be proportional to cosφGa, where φGa is a local incident angle of the Ga beam to a local crystal growing surface. Submicron-thick three-dimensional GaAs-Ga1−xAlxAs multilayers have been grown self-aligningly on corrugated structures with a 8-μm period. The layer thicknesses and AlAs compositions (x) are also interpreted by the local incident angles of Ga and Al beams, while evidence of atom diffusion is revealed.
The low-lying electronic states of Ar2F
Authors: Wadt Willard R. , Hay P. Jeffrey
Published: February 2003

A b initio POL-CI calculations are reported on the six lowest states of the Ar2F molecule for isosceles triangle (C2v) and linear Ar-Ar-F geometries. In the triangular configuration, the lowest Ar2+F− ionic state (2 2B2) is bound by 5.0 eV relative to Ar2+ (2Σ+u)+F− and by 0.6 eV relative to Ar+F− (2 2Σ+)+Ar. Emissions from this state to the repulsive states (1 2A1 and 1 2B2) dissociating to Ar+Ar+F are predicted at 268 and 274 nm with a combined lifetime of 128 nsec.
Backside-illuminated InAs1−xSbx-InAs narrow-band photodetectors
Authors: Cheung D. T. , Andrews A. M. , Gertner E. R. , Williams G. M. , Clarke J. E. , Pasko J. G. , Longo J. T.
Published: February 2003

High-performance backside-illuminated photodiodes have been fabricated for the first time from InAs1−xSbx-InAs heterostructures prepared by liquid-phase-epitaxy technique. The peak wavelength can be tuned compositionally from 3.1 to over 7.0 μm at 77 K. The half-width of the spectral responses as narrow as 1760 Å (at 4.0 μm) have been achieved. Internal quantum efficiencies of 90% and zero-bias-resistance–area products of 2×107 Ω cm2 have been obtained at 77 K.
Information-storage device using surface diodes
Authors: Kirkpatrick C. G. , Possin G. E. , Norton J. F.
Published: February 2003

A concept for a high-density memory-storage device is described. Information is recorded as small implanted p+ (or n+) diodes, formed by a focused ion beam, on the n+ (or p+) surface of a large-area diode and read by a focused electron beam. Preliminary experimental results using ion implantation through an aperture mask to simulate a focused ion beam, and a scanning electron microscope for readout, demonstrate better than 0.5-μ bit spacing. Evaluation indicates that 1010 bits/cm2 storage density is possible, with ≳10 Mbits/sec write/read rates, and access times <30 μsec to 1011-bit data fields.
On the establishment of an inversion layer in p- and n-type silicon substrates under conditions of high oxide fields
Authors: Solomon P. M.
Published: February 2003

It has been observed that an inversion layer cannot form in a p-type silicon substrate when the Fowler-Nordheim tunneling current into the oxide exceeds the minority generation current in the depletion layer. On the other hand, for n-type substrates, the formation of the inversion layer is unaffected by the oxide current.
The distribution of gold and oxygen in solid phase epitaxy Si films
Authors: Christou A. , Davey J. E. , Day H. M. , Dietrich H. B.
Published: February 2003

Silicon films deposited on Au/Si layers at deposition temperatures at or above 380 °C are single crystal, while Si films deposited on Si with a native oxide are amorphous up to 500 °C and ordered polycrystalline above 500 °C. The initial gold (300 Å) deposit migrates to the growing epitaxy surface where it nucleates in clusters. RBS and AES analysis indicated that 0.1 at.% gold remains distributed throughout the epitaxial film.
High-temperature Nb3Sn thin-film SQUID’s
Authors: Wu C. T. , Falco C. M.
Published: February 2003

We have fabricated thin-film Nb3Sn weak links and rf SQUID’s operating at temperatures ≳14.5 K. The properties of the weak links as well as the fabrication technique and operating characteristics of the SQUID’s are described.
High-energy gamma spectra detected with imporved HgI2 spectrometers at room temperature
Authors: Beinglass I. , Dishon G. , Holzer A. , Ofer S. , Schieber M.
Published: February 2003

The detection of the photopeak of the 662-keV γ ray of 137Cs with a full width at half-maximum (FWHM) of only 6.5 keV by a 0.5-mm-thick improved stoichiometry HgI2 crystal is reported. The 1173- and 1332-keV γ photopeaks of 60Co have also been resolved for the first time. Polarization effects were negligible.
Creep curve of silicon wafers
Authors: Isomae S. , Nanba M. , Tamaki Y. , Maki M.
Published: February 2003

A new method of performing a creep test on silicon single crystals is described. The experiment utilizes silicon wafers. The stress applied to the wafers is provided by a Si3N4 film deposited by chemical vapor deposition on the front side of the wafer. The samples, i.e., silicon wafers with superposed Si3N4 films, are annealed in a quartz tube at 1000–1100 °C. The creep curves obtained are classified into two types according to stress. One type is related to plastic deformation of the wafer; the other is an elastic deformation. These results are available for the use of Si3N4 film in semiconductor technology.
Photochemical diodes
Authors: Nozik A. J.
Published: February 2003

A simple new device configuration for the conversion of optical energy into chemical energy is described. The devices, designated ’’photochemical diodes’’, consist of small sandwichlike semiconductor structures. When immersed in an appropriate electrolyte and exposed to light, such devices cause redox reactions to occur, such as the decomposition of water, and the oxidation of sulfide ions to form sulfur. Certain configurations result in up-conversion of the incident photon energy and appear to represent an inorganic analog of photosynthesis.
A purely chemical HCl laser
Authors: Arnold S. J. , Foster K. D. , Snelling D. R. , Suart R. D.
Published: February 2003

The kinetics of the purely chemical production of nonequilibrium concentrations of Cl atoms from the ClO2/NO chain reaction is discussed. It is shown that this chemical system is suitable for producing Cl atoms to pump a cw HCl laser and that there are three modes of accomplishing the prepumping chemistry. A hybrid HCl/CO2 laser was operated using this chemistry which gave 7 mW output power at 10.6 μm. A transverse flow HCl laser was operated having a multiline output power of 13 W and a chemical efficiency of 8%. The three modes of accomplishing the chemistry were demonstrated with a transverse flow HCl laser.
n-indium tin oxide/p-indium phosphide solar cells
Authors: Sree Harsha K. S. , Bachmann K. J. , Schmidt P. H. , Spencer E. G. , Thiel F. A.
Published: February 2003

n-indium tin oxide/p-indium phosphide (n-ITO/p-InP) solar cells have been prepared by ion-beam deposition of indium tin oxide on p-InP single-crystal substrates. The cells have a solar power conversion efficiency of 14.4% at air mass 2 (AM2) when provided with antireflection coatings.
Sintered Ce-Co-Cu-Fe-Ti magnets
Authors: Inomata Koichiro , Oshima Teruo , Ido Tadashi , Yamada Masakazu
Published: February 2003

Ce(Co-Cu-Fe-Ti)z alloys were prepared with 5.6⩽z⩽7.4. They were ground into powders and sintered in Ar atmosphere. It was found that Ti enhanced coercivity and rectangularity. A permanent magnet with Br=7400 G, IHc=6100 Oe, (BH)max=13 MG Oe, and rectangular hysteresis loop was achieved on sintered samples having the composition Ce(Co0.727Fe0.12Cu0.14 Ti0.013)6.5.
Free-carrier plasma effects in ion-implanted amorphous layers of silicon
Authors: Spitzer W. G. , Waddell C. N. , Narayanan G. H. , Fredrickson J. E. , Prussin S.
Published: February 2003

A high-conductivity layer has been observed within the amorphous region of heavily implanted (6×1016 cm−2 of 2.7-MeV 31P ions) (111) surfaces of single-crystal Si after 500 °C annealing. The conducting layer was at the projected range of the 31P+ ions, and its location was determined from spreading resistance measurements. Microscopic examination, Coates-Kikuchi lines (SEM), and ion channeling showed that the conducting layer was within an amorphous region. Very-large-amplitude low-frequency ir interference reflection fringes developed with the onset of the conducting layer. We suggest that the large fringes are related to the dispersion produced by a damped plasma. Simplified model calculations are presented. The high-frequency interference fringes related to the implantation-induced structural damage virtually disappeared after annealing at 600 °C but the low-frequency ’’plasma fringes’’ remain. SEM and microscopic examination showed that the amorphous region had epitaxially recrystallized.
Surface-layer composition changes in sputtered alloys and compounds
Authors: Liau Z. L. , Brown W. L. , Homer R. , Poate J. M.
Published: February 2003

Compositional changes of binary alloys and compounds have been observed (by Rutherford backscattering techniques) as a result of rare-gas sputtering in the energy range 20–80 keV. After sputtering, the heavier components were generally found to be enriched in a surface layer whose thickness corresponded approximately to the range of the sputtering ion; the compositions of these enriched surface layers were independent of the mass and energy of the sputtering ions. This phenomenon of surface layer enrichment is interpreted as due to preferential sputtering from the surface in combination with defect-enhanced diffusion.
Uniform large-area high-gain silicon avalanche radiation detectors from transmutation doped silicon
Authors: Gelezunas V. L. , Siebt W. , Huth G.
Published: February 2003

Significant improvements in gain and energy resolution are reported for very-large-area p-n-junction-type silicon avalanche radiation detectors which were made from neutron-doped silicon. Detectors with frontal areas of about 20 mm2 had gains which ranged from 400 (1.2 keV FWHM at 5.9 keV) to over 800 (2.2 keV FWHM at 5.9 keV). A 330-mm2 device showed a maximum gain of 150 with an energy resolution of 16 keV FWHM at 22 keV.
The effect of ion implantation on the minimum bubble drive field in magnetic garnet films
Authors: Engemann J. , Hsu T.
Published: February 2003

The investigation of the minimum bubble drive field (ΔHz,min) in ion-implanted 5-μm magnetic garnet films shows that it depends strongly on the implantation conditions such as the implantation energy and dosage. With increasing implantation energy and dosage adjusted so that the maximum damage level remains constant, the ΔHz,min decreases monotonically. Varying the dosage while keeping the implantation energy constant leads to a pronounced minimum in ΔHz,min. Reductions of the ΔHz,min by as much as 43% from that of the as-grown films have been achieved by using proper ion implantations. The ΔHz,min in an ion-implanted film is found also to be dependent on the applied in-plane field Hip. With increasing Hip, the minimum drive field increases until finally the as-grown value is reached. This behavior as well as the dependence of ΔHz,min on the different ion implantations can be explained qualitatively by a model, assuming a capping layer somewhat buried in the garnet film.
A model for the formation of stacking faults in silicon
Authors: Mahajan S. , Rozgonyi G. A. , Brasen D.
Published: February 2003

A model for the evolution of stacking faults in silicon during oxidation and during aging of silicon containing oxygen is proposed. Based on the proposed mechanism, the observed role of dislocations, point-defect clusters constituting the swirl pattern, and abrasion-induced strain in the generation of stacking faults can be accounted for in a unified manner.
Acoustic pulse echo measurements at 200 MHz
Authors: Khuri-Yakub B. T. , Kino G. S.
Published: February 2003

We have carried out acoustic pulse echo measurement with 2-nsec-wide pulses. These are used to excite a zinc oxide layer deposited on a conically shaped sapphire buffer rod 2 mm in diameter at the tip of the cone. We have found that an easy way to make contact between the sapphire rod and a solid material under study is by means of a gold foil. We have measured the thickness of a nickel plating on aluminum of the order of 50 μm, and that of a 134-μm-thick glass slide to within 2%.
Wideband modulation of the C13O216 laser R (18) line at 10.784 μm with an N14H3 Stark cell
Authors: Asawa C. K. , Plant T. K.
Published: February 2003

Intense Stark resonance absorptions near 10.7 μm of the R (18) and R (24) lines and a weaker absorption of the R (26) line of the isotopic C13O216 laser by N14H3 are reported. Wideband modulation experiments with an N14H3 Stark cell and the R (18) line are presented. Key modulation features are the 2-ns rise time, high modulation depths, low power dissipation, short Stark modulator cell (10 cm), high saturation intensity (≳8 W/cm2), new spectral features of the modulated signal versus Stark bias, and a demonstration of 180-Mbit random word modulation.
A model for uv preionization in electric-discharge-pumped XeF and KrF lasers
Authors: Hsia J.
Published: February 2003

A mechanism is proposed to explain the improvement in discharge uniformity observed in pure electric-discharge-pumped rare-gas halide lasers when a uv preionizer is used to precondition the laser medium. In the model the F− ions formed by dissociative attachment following uv photoionization act as a reservoir from which electrons are easily released when the main discharge field is applied. The model shows that a time delay is required between the application of the uv and the main discharge, and also that the effect of the preionizer can last some tens of microseconds despite the large electron attachment rates in the laser mixture.
Picosecond XeF amplified laser pulses
Authors: Tomov I. V. , Fedosejevs R. , Richardson M. C. , Sarjeant W. J. , Alcock A. J. , Leopold K. E.
Published: February 2003

Picosecond third harmonic (353 nm) Nd : glass laser pulses have been amplified by factors of ≳6 000 in a high-pressure XeF discharge. Peak powers ∼50 kW have been observed.
30-psec CO2 laser pulses generated by optical free induction decay
Authors: Kwok H. S. , Yablonovitch Eli
Published: February 2003

We have measured the two-photon autocorrelation function of ultrashort CO2 laser pulses generated by optical free induction decay. The pulse duration was determined as a function of the pressure in the resonant absorber. At a pressure of 250-Torr 30-psec optical pulses were produced.
Angular distributions of x-ray line radiation from a laser-produced plasma
Authors: Chase L. F. , Jordan W. C. , Perez J. D. , Pronko J. G.
Published: February 2003

A method for measuring angular distributions of individual x-ray line intensities from laser-produced plasmas is described and applied to measure the strong angular dependence of lines from an aluminum plasma. The data are consistent with calculations made with a simple plasma model incorporating radiation reabsorption and transport in the plasma.
A comment on the methods of calculation of corona onset voltage
Authors: Salama M. M. A. , Parekh H. , Srivastava K. D.
Published: February 2003

Two methods of calculating corona onset voltage (cov) in nonuniform air gaps are studied. The variation of number of electrons (or positive ions) in primary and secondary electron avalanches for short (⩽20 cm) as well as long (2–10 m) positive point-to-plane air gaps is obtained. Several conclusions regarding critical charge carrier numbers are drawn from this study.
The effect of reabsorbed radiation on the minority-carrier diffusion length in GaAs
Authors: Ettenberg M.
Published: February 2003

Reported in this paper are the first experiments designed to separate the effects of reabsorbed recombination radiation (RRR) and diffusing minority carriers on the measured minority-carrier diffusion length. From light spot scan experiments on bevelled samples of p-type Ge-doped GaAs it was found that for p-layer thicknesses up to two diffusion lengths (10–20 μm) carriers created by RRR represent less than 10% of the total carriers diffusing from a generating source (illumination of p-n junction injection). Thus for measurements and structures of interest carriers created by RRR play no substantial role.
Intrinsic gettering by oxide precipitate induced dislocations in Czochralski Si
Authors: Tan T. Y. , Gardner E. E. , Tice W. K.
Published: February 2003

Conditions for effective intrinsic gettering by oxide precipitate induced dislocations, which we suggest as an important mechanism in explaining device leakage limited yield enhancement due to oxygen in Czochralski-grown Si wafers, are examined. The effectiveness of this mechanism is demonstrated.
Effect of second-phase precipitates and deposition temperature on the hysteretic losses in CVD-prepared Nb3Ge
Authors: Thompson J. D. , Maley M. P. , Newkirk L. R.
Published: February 2003

Hysteretic losses have been measured on a large number of Nb3Ge samples prepared by the chemical vapor deposition process. These measurements were performed as a function of induced current and temperature on samples which contained differing amounts of second-phase material, Nb5Ge3. It was found that very low 50-Hz losses, on the order of 20 μW/cm2 at 500 rms A/cm and at temperatures of up to 12 K, could be attained in as-deposited material. An apparent correlation between the critical current density and the Nb5Ge3 content was observed, which suggested that enhanced pinning due to the second-phase precipitates was responsible for these low losses.
Chirped-grating output couplers in dielectric waveguides
Authors: Katzir A. , Livanos A. C. , Yariv A.
Published: February 2003

This paper reports on the method of fabrication and first experiments of chirped (variable period) gratings in a dielectric waveguide. Such gratings, which are proposed as a new optical building block, are used in this work as focusing output couplers.
A chirping laser for photochemical applications
Authors: Steverding B.
Published: February 2003

The efficiency increase of photochemical reactions by a chirping laser is discussed. The optimal detuning rate is calculated for constant intensity pulses and for pulses with linear rise. Calculating a particular example for BCl3, it is shown that photochemical efficiency can be increased by an order of magnitude.
A discharge-pumped ArCl superfluorescent laser at 175.0 nm
Authors: Waynant Ronald W.
Published: February 2003

Initial observations have been made of laser action in ArCl excimers pumped by a high-voltage fast-rise-time Blumlein discharge circuit. The new laser emits at 175.0 nm and operates at atmospheric pressure. The gas from which the molecules are formed consists of 1% Cl2, 15% Ar, and 84% He. A gain coefficient of 0.012 cm−1 has been determined for ArCl.
Diffraction-limited KrF and XeF lasers with a negative-branch unstable resonator
Authors: McKee T. J. , Stoicheff B. P. , Wallace Stephen C.
Published: February 2003

Diffraction-limited performance has been achieved in discharge-excited KrF and XeF lasers by using an unstable resonator configuration. A peak power of 5 MW (50 mJ) was produced from a Blumlein circuit with stored energy of only 5 J.
Viscous flow of thermal SiO2
Authors: EerNisse E. P.
Published: February 2003

Wafer curvature measurements from 25 to 1075 °C are used to demonstrate viscous flow of thermally grown SiO2 at temperatures as low as 960 °C. Both O2- and steam-grown oxides are examined and found to have viscosities similar to synthetic fused silica. It is recommended that high-temperature Si device processing involving SiO2 be held to below 960 or even 925 °C, after oxide growth to avoid viscous flow and the accompanying structural damage in the oxide. This recommendation holds particularly for device technologies where resistance to ionizing radiation is important. The measurements also demonstrate that gross structural damage resides in the Si beneath steam-grown oxide.
Tunable infrared generation by coherent Raman mixing in H2
Authors: Brosnan S. J. , Fleming R. N. , Herbst R. L. , Byer R. L.
Published: February 2003

We have generated continuously tunable infrared output between 3.5 and 13 μm by coherent Raman mixing in H2 gas at 20 atm using a Nd : YAG laser-pumped LiNbO3 parametric oscillator as the input source. The coherent Raman mixing method offers significant advantages over stimulated Raman scattering for frequency conversion.
A time-dispersion-tuned fiber Raman oscillator
Authors: Stolen R. H. , Lin Chinlon , Jain R. K.
Published: February 2003

By using a novel time-dispersion-tuning scheme a fiber Raman oscillator pumped by a mode-locked argon laser has been tuned within the broad Raman gain bandwidth (∼400 cm−1) of silica glass by varying the resonator length. A tuning range of 40 Å in the green is obtained with an average pump power of 1.6 W. A combination of time dispersion and prism tuning extends this range to 134 Å (5153–5287 Å). Tunable Raman oscillation with lower threshold in the 1-μ region should be possible with a mode-locked Nd : YAG laser pump.
A colloid-SEM method for the study of fine magnetic domain structures
Authors: Goto K. , Sakurai T.
Published: February 2003

A simple method to obtain fine magnetic domain patterns is described. The method has two processes, the first is to make the usual Bitter patterns and the second to observe dried colloidal particles on domain boundaries by a scanning electron microscope (SEM) in the secondary electron mode. Micrographs of domain patterns of hexagonal cobalt have been shown at magnifications of SEM from 2000 to 5000. Owing to the large focal depth of SEM, it is able to observe domains on both surfaces of a crystal edge at the same time, and examples have been shown.
The coherent interaction of externally generated 35-GHz sound with the light in CdS
Authors: Suzuki Sohbe , Nishizawa Jun-ichi , Suto Ken
Published: February 2003

The first experiment of backward collinear diffraction of light in CdS by 35-GHz ultrasonic waves is reported.
Effect of nonparabolicity on transverse magnetoresistance in nondegenerate semiconductors
Authors: Wu Chhi-Chong , Chen Anna
Published: February 2003

The effect of nonparabolicity on transverse magnetoresistance in nondegenerate semiconductors has been investigated taking into account the inelasticities in the electron-phonon scattering due to the finite energy of he phonons involved. Our numerical results are shown to be in qualitative agreement with experimental results in the quantum limit. It is found that the nonparabolicity causes the nature of its temperature dependence to change as computed for the case of parabolicity.
Optical display device using bistable electrets
Authors: Bruneel J. L. , Micheron F.
Published: February 2003

The bistable mechanical motion of a corona-charged polypropylene film in the electric field developed between two electrodes is used in the construction of a new transmission light gate. The minimum switching voltage and time are, respectively, 500 V and 50 ms, in accordance with the proposed motion model. Optical and electrical characteristics of an electret display device using a 5×3 array of light gates are presented.
Production of megawatt submillimeter pulses by stimulated magneto-Raman scattering
Authors: Granatstein V. L. , Schlesinger S. P. , Herndon M. , Parker R. K. , Pasour J. A.
Published: February 2003

Pulses of submillimeter radiation (λ∼400 μm) with a peak power of approximately 1 MW have been generated by illuminating an intense relativistic electron beam with a counterstreaming microwave pump wave (λ∼2 cm). This observation of powerful submillimeter radiation is consistent with a model of stimulated scattering which includes a resonance between the pump wave frequency and the electron cyclotron frequency as well as the occurrence of electrostatic oscillations at the beam plasma frequency.
Pulsed laser heating of thin opaque targets in air
Authors: Robin James E.
Published: February 2003

A simple analytical model has been developed which describes the heating of a thin opaque target in air when subjected toirradiation from a high-power pulse laser. Effects due to the formation of a laser supported absorption wave (LSAW) above the target surface are explicitly included in this model. The results shows that despite the increased coupling due to the presence of the LSAW, the resultant target heating from a tightly focused beam (small spot diameter) can be severely retarded by energy spreading as the LSAW expands over the target surface.
Analytical photon catalysis: Measurement of gas phase concentrations to 104/cm3
Authors: Capelle Gene A. , Sutton David G.
Published: February 2003

A new analytic technique was developed to determine quantitatively the concentration of gas-phase species at concentrations well below the measurement capabilities of atomic absorption and mass spectroscopy. The method involves injecting an excess of an energetic metastable species, N2(A3Σ+u) in this experiment, into a gas stream containing the species to be measured, Bi in this case. Energy transfer from the metastable to the sample species results in excitation and subsequent rapid emission of light. The intensity of the light emitted at the wavelengths characteristic of the sample species is a function of, and hence a measure of, the concentration. Concentrations as low as 1.5×104/cm3 were measured. Greater sensitivity is possible with more efficient optical detection.
Ion implantation as an ultrafast quenching technique for metastable alloy production: The Ag-Cu system
Authors: Poate J. M. , Borders J. A. , Cullis A. G. , Hirvonen J. K.
Published: February 2003

Substitutional solid solutions of Ag in Cu have been formed by ion implanting Ag at concentrations up to 16 at.%. The physical states of the implanted alloys were deduced by ion channeling and transmission electron microscopy and their stability was examined by annealing to 400 °C. The implantation results are compared with those obtained previously by conventional rapid quenching techniques.
The effect of the anneal ambient on implanted GaAs and the occurrence of compensated regions in Si implants
Authors: Antell G. R.
Published: February 2003

It has been shown that the ease with which Ga can diffuse through an SiO2 film on a Si-ion-implanted sample of GaAs can be used to advantage to change the stoichiometry of the sample by annealing in an ambient consisting of H2+HCl+GaCl. The use of the same ambient with a Se-implanted sample leads to a reduction in both the mobility and the degree of activation. Both bulk and epitaxial samples which had been coated with either SiO2 or Si3N4 and implanted to 1015 cm−2 with 400-keV Si ions were found to contain compensated or p-type regions after annealing at 900 °C. A model is suggested to account for this effect.
Evaluation of cadmium stannate films for solar heat collectors
Authors: Haacke G.
Published: February 2003

Optical transmission and reflection data are reported for Cd2SnO4 films coated onto transparent substrates or silicon. It is shown that these coatings are candidates for transparent heat reflectors and selective absorber components in solar heat collectors.
Plasma production by irradiating freely falling deuterium pellets with a high-power laser
Authors: Baumhacker H. , Brinkschulte H. , Lang R. S. , Riedmüller W. , Salvat M.
Published: February 2003

A high-power Nd : glass laser beam was focused on freely falling deuterium ice pellets. It was demonstrated that this method allows reliable and reproducible production of an isolated deuterium plasma cloud suitable for filling a plasma machine. The plasma with a total ion number of (1–2) ×1017 expands quite uniformly at a velocity of (1–3) ×107 cm/s. However, the pellet is not completely ionized, which is in accordance with theoretical predictions. The greater portion of the pellet disintegrates after the laser shot and expands with a velocity of approximately 1×106 cm/s.
Doppler-free optical double-resonance Stark spectroscopy using modulation sidebands
Authors: Orr Brian J. , Oka Takeshi
Published: February 2003

An electro-optic modulator, driven at a single radio frequency ν, is used to create sidebands (νL±ν) on the frequency νL of a cw single-mode CO2 laser. Laser-induced line narrowing in molecular Stark spectroscopy is demonstrated, using double resonances of the copropagating waves at νL and (νL±ν) with pairs of coupled Doppler-broadened transitions. Doppler-free Stark spectra of the molecules PH3, 13CH3F, and 12CH3F are used to illustrate the technique. For PH3 it is found that the electric dipole moment vibrational difference ‖μ (v2=1)−μ (v=0) ‖⩽0.005 D.
High-repetition-rate XeF laser with gas recycling
Authors: Christensen C. P.
Published: February 2003

Sustained operation of a Blumlein-driven XeF excimer laser at pulse repetition rates as high as 200 pps has been achieved. A simple technique for reclamation and recycling of xenon used in the laser gas mixture is also reported.
Complete compensation of self-phase modulation in cesium vapor at 1.06 μ
Authors: Lehmberg R. H. , Reintjes J. , Eckardt R. C.
Published: February 2003

We have observed a complete cancellation of self-phase modulation in 1.06-μ pulses propagating through cesium vapor. The negative nonlinear refractive index responsible for this is measured as n2/N=−(2.5±0.5) ×10−30 esu, in good agreement with the theoretical value −2.62×10−30 esu.
An isothermal etchback-regrowth method for high-efficiency Ga1−xAlxAs-GaAs solar cells
Authors: Woodall J. M. , Hovel H. J.
Published: February 2003

High-efficiency p-Ga1−xAlxAs, p-GaAs, n-GaAs solar cells are made by isothermally soaking n-GaAs substrates in an undersaturated Zn-doped Ga-Al-As melt. This one-step growth procedure produces a graded band gap p-Ga1−xAlxAs layer 0.2–0.4 μm thick. Efficiencies of 18.5% AM0 and 21.9% AM1 have been measured.
Three-body quenching of KrF* by Ar and broad-band emission at 415 nm
Authors: Mangano J. A. , Jacob J. H. , Rokni M. , Hawryluk A.
Published: February 2003

A kinetic model for the formation and quenching of KrF* (2Σ1/2) that is applicable for electron-beam-excited mixtures of Ar/Kr/F2 containing ⩽15% Kr is presented. The product of the rate constant for the postulated three-body quenching process (KrF* +2 Ar→ArKrF*+Ar) and the KrF* lifetime is determined to be 5.2 ×10−40 cm6. An exchange reaction (Kr+ArKrF*→Kr2F*+Ar) rapidly leads to the formation of Kr2F* whose emission is observed in a broad band centered at 415 nm. The KrF* laser saturation flux is given in terms of measured parameters and the mixture number density; for a 1-atm mixture with 0.3% F2 and 1% Kr it is 0.85 MW/cm2.
Optically cascaded pulsed DF chemical laser
Authors: Osche G. R.
Published: February 2003

The optical extraction efficiencies and temporal characteristics of a pulsed optically cascaded SF6+D2 chemical laser are presented. It is shown that the directly coupled cascade P3(7) →P2(8) →P1(9) yields approximately 53% of the total multiline energy, while the rotationally coupled cascade P3(6) →P2(8) →P1(10) and the mixed cascade P3(6) →P2(8) →P1(9) are slightly less efficient. Cavity parameters, relative emission strengths, and natural delay times for oscillation of P lines are shown to have a strong influence on the total peak power.
vuv emissions from mixtures of F2 and the noble gases—A molecular F2 laser at 1575 Å
Authors: Rice James K. , Hays A. Kay , Woodworth Joseph R.
Published: February 2003

We have observed two new emission features in electron-beam-excited mixtures of molecular fluorine with either neon or helium. One feature is a continuum centered at 1080 Å which we attribute to NeF*. The other emission feature is a band system extending from 1500–1600 Å which we attribute to a transition of molecular fluorine. This transition lased near 1575 Å.
Interstitial potential differences, electronegativity differences, and effective ionic charges in zinc-blende-type semiconductors
Authors: Frensley W. R. , Kroemer H.
Published: February 2003

Simple semi-empirical self-consistent pseudopotential calculations of various semiconductors, fitted to the empirical band structures, lead to interstital potential differences that can be described by an ionic model such that the ionic charges are proportional to the differences of the PHillips electronegativities for the participating ion species, e*/e≃0.76𝒟X. The results are applied to dipole corrections in heterojunction lineups.
Reflection of magnetostatic surface wave at a shallow groove on a YIG film
Authors: Parekh J. P. , Tuan H. S.
Published: February 2003

A field theory for the magnetostatic surface wave (MSSW) reflectivity of a single shallow groove etched on top of an epitaxial YIG film is presented. Computed reflection characteristics are obtained for the case in which the grooved YIG film is unmetallized, and compared to corrected results for a metallized geometry. The conditions under which the MSSW reflctivity of a groove is significantly larger than the SAW reflectivity of an equivalent groove on a LiNbO3 substrate are pointed out.