bluuebunny/crossref_metadata_2025 huggingface dataset:
Microwave mixing with niobium variable thickness bridges
Authors: Wang Li-Kong , Callegari Alessandro , Deaver Bascom S. , Barr Daniel W. , Mattauch Robert J.
Published: February 2003

Niobium thin-film bridges 300 Å thick, 1 μm wide, and 0.5 μm long joining two bulk films 5000 Å thick and having normal resistance of ∼1 Ω have been fabricated and used for microwave mixing at 10 GHz. They exhibit Josephson, bolometric, and multiple-flux-flow mixing and have useful response at 100–200 GHz. The data show in a direct way limitations imposed by flux flow and heating.
Saturable absorber overlap of iodine 127 with the optically pumped 546-nm mercury laser
Authors: Artusy Max , Siegman A. E.
Published: February 2003

A single isolated saturated-absorption feature in 127I2 using the optically pumped 546.1-nm Hg laser has been observed with low (∼6 MHz) resolution. The 3S1→3P2 Hg laser transition can be centered exactly on this feature by varying the N2 buffer gas pressure using the measured pressure tuning rate of −9.4 MHz/Torr. This may provide an attractive laser system for absolute wavelength stabilization.
Electron-beam switching of thin-film ZnS electroluminescent devices
Authors: Howard W. E. , Alt P. M.
Published: February 2003

An electron beam of moderate current density (∼10−5 A/cm2) and energy (10–16 keV) has been used to change the luminance state of a thin-film ZnS : Mn electroluminescent device having hysteretic or memory-type behavior with respect to applied voltage. The dwell time of the beam required for writing is of the order of 0.05–1 ms, depending upon applied voltage and beam current density. The change in luminance is confined to the area bombarded and persists for hours, decaying approximately as erf(αt−1/2) for 50<t<104 s.
InxGa1−xAsyP1−y/InP heterojunction photodiodes
Authors: Wieder H. H. , Clawson A. R. , McWilliams G. E.
Published: February 2003

The photoelectronic properties of quaternary alloy heterojunction photodiodes made of liquid-phase-grown In0.88Ga0.12As0.25P0.75 layers deposited onto p-doped InP substrates have been investigated experimentally and analytically. It is shown that a typical photodiode with a peak responsivity of 0.26 A/W (at 1.02 μm) has a quantum efficiency of ∼22% at 1.06 μm.
A light-controlled light modulator
Authors: Grischkowsky D.
Published: February 2003

A fast resonantly enhanced light-controlled light modulator is demonstrated. Optical switching action is obtained with driving laser pulses with intensities as low as 2 kW/cm2. The switching mechanism is the optical nonlinearity due to adiabatic following for the single photon resonance.
High-resolution polymer replication of surface topography
Authors: Hiraoka Hiroyuki
Published: February 2003

A few micron wide and thick polymer lines are formed from a monomer, methacrylic anhydride, according to a metal pattern of a mask under high-energy radiation, such as γ rays. The resolution is limited only by the mask configuration; with our present mask configuration it is better than ∼2000 Å. The polymerization is initiated by electrons ejected from metal lines.
Confined-carrier luminescence of a thin In1−xGaxP1−zAsz well (x∼0.13, z∼0.29, ∼400 Å) in an InP p-n junction
Authors: Rezek E. A. , Shichijo H. , Vojak B. A. , Holonyak N.
Published: February 2003

A thin (∼400 Å) LPE In1−xGaxP1−zAsz ’’trap’’ on the p-type side of an InP junction [Eg(InP)−Eg(InGaPAs) ≡ΔE∼245 meV], is filled by injection to a high enough density to make it possible to observe confined-particle states and laser modes in a 70-meV (≳600 Å) range. The position of the modes is in good agreement with the transition energies expected for a finite potential well.
Effects of facet coatings on the degradation characteristics of GaAs-Ga1−xAlxAs DH lasers
Authors: Shima Y. , Chinone N. , Ito R.
Published: February 2003

Facet damage which is one of the major mechanisms of slow degradation has been virtually eliminated with Al2O3 facet coatings. Al2O3 half-wave films deposited by the conventional CVD method have been found to be effective not only for minimizing facet erosion but also for increasing the catastrophic failure limit by about a factor of 2.
GaAs waveguide detectors for 1.06 μm
Authors: Nichols K. H. , Chang W. S. C. , Wolfe C. M. , Stillman G. E.
Published: February 2003

GaAs electroabsorption avalanche photodiodes in n-n+ GaAs waveguides have been used to detect the 1.06-μm radiation from a Nd : YAG laser with a responsivity of 125 A/W and an internal quantum efficiency of 23%. The response at this wavelength is due to a combination of band-to-band and defect-to-band electroabsorption.
Negative resistance in a triple-barrier structure of Al-Al2O3
Authors: Takabe Sadao , Yasui Kanji , Kaneda Shigeo
Published: February 2003

An experimental study of tunneling currents in thin multilayers of Al-Al2O3 has been performed. Negative resistances are observed at 77 °K in a triple-barrier structure. It is considered that these negative resistances are caused by the effect of resonant tunneling, compared to the theoretical consideration of quasistationary energy levels in such a structure.
A new acoustophotorefractive effect in lithium niobate
Authors: Berg N. J. , Udelson B. J. , Lee J. N.
Published: February 2003

A new photorefractive effect resulting from the interaction of high-intensity short-duration laser pulses with propagating acoustic waves has been found to occur in LiNbO3. The index-of-refraction change (δn) is proportional to the rf signal and increases sublinearly with the number of laser pulses and as the 1.3 power of the incident laser energy density (J) per pulse. The decay time of δn varies from a few hours when only green illumination (530 nm) is used to several weeks when combined green and infrared illumination (1060 nm) are used. This acoustophotorefractive effect can be utilized to construct an acousto-optic memory correlator.
Superconducting weak links induced by optical guided waves
Authors: Gilabert A. , Ostrowsky D. B. , Vanneste C. , Papuchon M. , Puech B.
Published: February 2003

Superconducting weak links have been created by locally weakening the superconductivity of a narrow thin-film lead strip via the evanescent field of an optical guided wave. Existence of the Josephson junction behavior of these links was confirmed by examination of their behavior in applied magnetic fields.
uv fluorescence of cerium-doped lutetium and lanthanum trifluorides, potential tunable coherent sources from 2760 to 3220 Å
Authors: Yang K. H. , DeLuca J. A.
Published: February 2003

Broad-band uv flurescence is reported for LaF2 : Ce3+ (2760–3120 Å) and LuF3 : Ce3+ (2880–3220 Å). The five-peak excitation spectrum expected for the 5d state of Ce3+ in a noncubic crystal field is observed. The fluorescence quantum yields for LaF3 : 1% Ce3+ and LuF3 : 0.1% Ce3+ are 0.9 and 0.82, respectively. Estimates of the threshold power for lasing action suggest that a laser system tunable from 2760 to 3220 Å is feasible with noble-gas–halide lasers as pumping sources.
A model of switching and negative resistance phenomenon in organic thin film with dipoles
Authors: Chiang Chun
Published: February 2003

Thin films formed by organic molecules with dipoles may switch at a threshold voltage; the switching is due to the flip-flop of the dipoles. Theoretically derived equations agree well with the experiment.
Channeling studies of radiation damage in metal-silicides
Authors: Ishiwara Hiroshi , Hikosaka Kohki , Furukawa Seijiro
Published: February 2003

Channeling effect measurements have been employed to investigate radiation damage produced by 100-keV Ar ions in preferred oriented polycrystalline metal-silicide layers, such as Pd2Si and NiSi2 layers formed on single-crystalline Si. For room-temperature implantation, an amount of the damage in Pd2Si layers was found to saturate at doses between 3×1014 and 1×1017 ions/cm2, where the minimum aligned yield of 1.5-MeV He ions was nearly 40% of the random one. On the contrary, it was observed that the NiSi2 layers became amorphous at doses higher than 3×1015 ions/cm2. These results were confirmed by the reflection electron diffraction analyses.
Line acoustic waves on cleaved edges
Authors: Datta Supriyo , Hoskins Michael J. , Hunsinger Bill J.
Published: February 2003

The feasibility of fabricating wedges suitable for wave propagation by cleaving LiNbO3 is demonstrated. This is a simple technique that affords excellent control over the wedge angle. The velocity and field distribution of line waves along the cleaved edge are predicted well from theory.
Ion-implanted selenium profiles in GaAs as measured by secondary ion mass spectrometry
Authors: Lidow A. , Gibbons J. F. , Deline V. R. , Evans C. A.
Published: February 2003

Depth profiles of Se-implanted GaAs samples have been measured using secondary ion mass spectrometry (SIMS). Analyses performed on liquid-nitrogen and room-temperature implants into Cr-doped substrates indicate that Se diffusion during subsequent heat treatment is negligible when the samples are annealed at 1000 °C for 15 min. A 12-h anneal at 1000 °C does, however, produce a diffused profile but with a diffusion constant of 2.8×10−15 cm2/sec as compared with the value 1×10−13 cm2/sec for thermal diffusion of Se at this temperature.
A new interimpurity recombination in GaP; revised values for acceptor binding energies
Authors: Sturge M. D. , Vink A. T. , Kuijpers F. P. J.
Published: February 2003

We have observed the radiative recombination of electrons, attached to nitrogen pairs, with holes on neutral acceptors. The acceptor binding energies are found to be 102.5±1 meV for Cd, 70.1±1 meV for Zn, and 54.7±1 meV for C, 8.3 meV larger than previously accepted values. This result implies corresponding increases in the band gap and exciton binding energy, to 2.350±0.002 eV and 22±2 meV, respectively, at 2 K.
X-band singly degenerate parametric amplification in a Josephson tunnel junction
Authors: Mygind J. , Pedersen N. F. , Soerensen O. H.
Published: February 2003

Preliminary measurements on a (quasi-) degenerate parametric amplifier using a single Josephson tunnel junction as the active element is reported. The pump frequency is at 18 GHz and the signal and idler frequencies are both at about 9 GHz. A power gain of 16 dB in a 4-MHz 3-dB bandwidth is achieved at the top of the cryostat.
Dissociative attachment of electrons to Br2 and HBr
Authors: Trainor Daniel W. , Boness M. J. W.
Published: February 2003

Electron attachment to Br2 and HBr has been studied over a range of E/P values using a high-pressure electron-beam-sustained gas-discharge apparatus. Experiments were performed in gas mixtures containing the attaching species and a large excess (⩾99%) of N2 which was included to control the electron temperature. Values of the dissociative attachment rate constants at an average electron energy near 1.0 eV for Br2 and HBr were found to be 1.0×10−10 and 8×10−10 cm3/sec, respectively. Using the known electron energy dependence of the dissociative attachment cross section, the magnitude of the dissociative attachment cross section for HBr was estimated.
Low-stagnation-temperature characteristics of cw N2O and CO2 gasdynamic mixing lasers pumped by nitrogen or air
Authors: Milewski J. , Brunné M. , Stańco J. , Zieliński A. , Irczuk M. , Rabczuk G. , Demin A. I. , Kudriavtsev E. M. , Volkov A. Yu. , Sobolev N. N.
Published: February 2003

Experimental data collected from a N2O/N2(air) thermally excited and selectively pumped cw gasdynamic mixing laser are reported for a range of low stagnation temperatures and compared with data from a CO2/N2(air) laser. Lasers operating with air yield practically identical output as with usual nitrogen pumping.
Argon bubble formation in the sputtering of PtSi
Authors: Liau Z. L. , Sheng T. T.
Published: February 2003

Argon bubble formation has been observed by Rutherford backscattering spectrometry and cross-sectional transmission electron microscopy in PtSi sputtered by Ar ions of 20–160 keV. The backscattering data show the bubble formation process to be repetitive. This phenomenon is interpreted in terms of Ar release due to the sputter etching.
Instability onset in electron-beam-sustained KrF* laser discharges
Authors: Brown Robert T. , Nighan William L.
Published: February 2003

Measurements of instability onset in a spatially uniform electron-beam-sustained KrF* laser discharge have shown that the time at which instability occurs decreases from about 1 to 0.1 μsec as E/n is increased in the range required for efficient laser operation. This finding is in good agreement with computed ionization instability onset times determined on the basis of a comprehensive model of the discharge.
Long-pulse N2 uv laser from a N2-CF4 mixture
Authors: Collier F. , Thiell G. , Cottin P.
Published: February 2003

Using a long-duration transverse discharge (300 ns) preionized by a short-pulse electron-beam gun (10 ns), laser emission has been obtained in the second positive system of nitrogen at λ=3371 Å in nitrogen alone and at λ=3577 Å in a N2-CF4 mixture. In the latter mixture, the laser emission lasts for 70 ns which is much longer than the radiative lifetime of the upper laser level C 3Πu(τF=40 ns). We think that the blottleneck of the terminal laser level is avoided thanks to the vibrational deactivation of the nitrogen B 3Πg state due to the irreversible transfer of vibrational energy of N2 to CF4 during collisions.
Direct measurement of gain recovery in a saturated Nd-glass amplifier
Authors: Martin W. E. , Milam D.
Published: February 2003

The temporal dependence of the gain recovery in a Nd-silicate glass amplifier has been directly observed after the passage of a short intense saturating laser pulse. The gain recovery time constant measured for ED-2 glass is 1.25±0.2 nsec. A striking polarization dependence of gain saturation recovery is observed.
Measurements of the absorption edge in fused silica
Authors: Kaminow I. P. , Bagley B. G. , Olson C. G.
Published: February 2003

The absorption coefficients of four commercial silicas (Spectrosil WF, Spectrosil A, Suprasil W2, Suprasil 2) have been measured over the energy range 6.2–8.1 eV. The absorption in the neighborhood of the edge varies markedly with water content. A peak or a shoulder is observed at 7.6 eV (an energy below the absorption edge) in the water-free samples. In samples containing significant OH, no structure at energies lower than the fundamental edge is observed. The absorption edge for the dry silica occurs at an energy 0.2 eV higher than for the wet silica.
Electro-optic guided-to-radiation mode conversion in Cu-diffused LiTaO3 waveguide with periodic electrodes
Authors: Okamura Y. , Yamamoto S. , Makimoto T.
Published: February 2003

We report electro-optically controlled guided-to-radiation mode conversion at 0.63-μm wavelength in a waveguide formed by electrodiffusing Cu ions in a c-plate crystal of LiTaO3. The efficiency of conversion from TE1 guided mode to TM radiation modes was measured by a low-frequency (0.5 kHz) modulation experiment with special attention paid to the dependence of the modulation efficiency on the longitudinal period of coplanar electrodes. Maximum mode conversion was observed at a 298-μm period where the efficiency was 21%/cm (16% for actual interaction length of 7.4 mm) with an applied voltage 600 V across the 45-μm gap. With a slight deviation (±10 μm) in the period, the efficiency was decreased to less than 10%/cm and its sensitivity is attributed to the change in the transverse field overlap of the coupled modes.
Getter sputtering at low temperature (≃20 °K)
Authors: Hauser J. J.
Published: February 2003

Getter sputtering with substrate temperatures as low as 18 °K was achieved by sputtering in helium gas with liquid helium circulating through the substrate table. This technique is effective in producing amorphous films from usually crystalline materials as a result of the low deposition temperature and of the high helium gas pressure necessary to obtain a sputtering current.
Measurement of effective mass in In0.9Ga0.1As0.22P0.78 by Shubnikov–de Haas oscillations
Authors: Restorff J. B. , Houston Bland , Burke J. R. , Hayes R. E.
Published: February 2003

The 0 K electron effective mass in an In0.9Ga0.1As0.22P0.78 epitaxial layer has been calculated from the temperature dependence of Shubnikov–de Haas oscillation amplitudes, giving m*=0.060m0. The measured value is compared to values m*=0.059m0 and m*=0.058m0 obtained from interpolations of the masses of related binary compounds by two different methods.
Exact analysis of mode interaction phenomena in integrated optics: Application to acousto-optics
Authors: So V. , Normandin R. , Stegeman G. I.
Published: February 2003

A new theory of coherent mode interactions in integrated optics is described with particular reference to light scattering by surface waves. This analysis is characterized by exact solutions to polarization-driven wave equations and electromagnetic boundary conditions.
Photoionization of uranium atoms by an argon ion laser
Authors: Mochizuki T. , Morikawa M. , Yamanaka C.
Published: February 2003

The pohotoionization of uranium atoms by the 3511- and 3345-Å uv lines from an argon ion laser was observed and attributed to resonant two-photon ionization. Application to uranium laser isotope separation is discussed.
Laser-driven shock wave inside a glass microballoon target
Authors: Azechi H. , Oda S. , Tanaka K. , Norimatsu T. , Sasaki T. , Yamanaka T. , Yamanaka C.
Published: February 2003

A shock wave in fusion fuel filled in a glass microballoon target was directly observed. The shock speed and the width of the shock front were 5×107 cm/s and a few μm, respectively, which are in good agreement with the shock-tube theory.
Radiation-induced conduction under high electric field (1×106 to 1×108 V/m) in polyethylene-terephthalate
Authors: Maeda H. , Kurashige M. , Ito D. , Nakakita T.
Published: February 2003

Radiation-induced conduction in polyethylene-terephthalate (PET) has been measured under high electric field (1.0×106 to 1.6×108 V/m). In a 6-μm-thick PET film, saturation of the radiation-induced current occurs at field strengths above 1.2×108 V/m. This has been demonstrated by the thickness and dose rate dependence of the induced current. Radiation-induced conductivity increases monotonically with field strength, then shows a saturation tendency. This may be explained by geminate recombination. Above 1×108 V/m, slowly increasing radiation-induced current appears. This may be caused by electron injection from the cathode, enhanced by the accumulation of the hetero space charges near it.
Physical and electrical properties of laser-annealed ion-implanted silicon
Authors: Gat A. , Gibbons J. F. , Magee T. J. , Peng J. , Deline V. R. , Williams P. , Evans C. A.
Published: February 2003

The use of a laser as a tool for annealing of ion-implantation damage is described. The principal results obtained are as follows: (1) electrical measurements show that activity comparable to that of a 1000 °C 30-min anneal can be obtained; (2) TEM measurements show that complete recrystallization of the damaged layer occurs during the laser anneal; (3) impurity profiles obtained from SIMS measurments show that the dopant atoms remain in the LSS profile during annealing. Simple diodes were fabricated to examine the feasibility of the method for device fabrication.
Optical surface waves in periodic layered medium grown by liquid phase epitaxy
Authors: Ng W. , Yeh P. , Chen P. C. , Yariv A.
Published: February 2003

Optical surface waves propagating along the surface of a multilayer stack have been observed. The multilayer stack is grown by liquid phase epitaxy. The transverse intensity distribution measured is found to agree with our theoretical calculation.
Optical pulse integration and chirp reversal in degenerate four-wave mixing
Authors: Marburger J. H.
Published: February 2003

A simple theory shows that phase modulation on a pulse may be reversed in time (e.g., positive chirp to negative) by degenerate four-wave mixing in an optically thin nonlinear medium. In thick media, the reflected pulse field is not truly time reversed, but is proportional to the time integral of the conjugate incident field.
Scattering of light from Rayleigh waves
Authors: Sung C. C.
Published: February 2003

The diffracted intensity of light scattered from surface (Rayleigh) waves is calculated by satisfying all boundary conditions to first order in the surface displacements. Comparison with existing experimental data and previous theoretical results is made, and several discrepancies are indicated. More importantly, the relative positions of the Brewster angles for the various diffracted orders appear to the reversed, experimentally, from those predicted in the present treatment.
The significance of the distribution of hot spots on the interpretation of laser produced plasma experiments
Authors: Arad B. , Eliezer S.
Published: February 2003

It is shown here that experimental results from different laser devices cannot be compared unless proper care is taken of the distributions of the hot spots.
Buried heterojunction electroabsorption modulator
Authors: Campbell J. C. , DeWinter J. C. , Pollack M. A. , Nahory R. E.
Published: February 2003

We describe the successful operation of a buried heterojunction electroabsorption modulator. This modulator, fabricated from AlyGa1−yAs1−xSbx/GaAs1−x′Sbx′, is particularly well suited for use with narrow spectral width sources such as the Nd : YAG fiber lasers. The GaAs1−x′Sbx′ crystal composition can be adjusted to permit operation in the wavelength range 0.9–1.2 μm. At 1.06 μm we have obtained an extinction ratio of 13 dB and a projected insertion loss of 4.0 dB. The low device capacitance permits operation at greater than 900 MHz.
Generation of tunable radiation below 2000 Å by phase-matched sum-frequency mixing in KB5O8⋅4D2O
Authors: Paisner J. A. , Spaeth M. L. , Gerstenberger D. C. , Ruderman I. W.
Published: February 2003

We have investigated second harmonic generation (SHG) and sum-frequency mixing (SFG) in deuterated potassium pentaborate using N2 laser pumped dye lasers. The crystal 90° second harmonic generates at 2161.5 Å with a power conversion efficiency of 5% at an input power of 15 kW. Tunable phase-matched VUV SFG is observed from 2161.5 to 1962.4 Å. Transmission and birefringence measurements indicate that the crystal can phase match with high conversion efficiencies to below 1700 Å.
Low-temperature behavior of pyroelectric glasses
Authors: Grout P. J. , March N. H. , Ohmura Y.
Published: February 2003

For pyroelectric glasses, the nonapplicability of the Third Law of Thermodynamics is shown to imply that the pyroelectric coefficient p (T) remains nonzero as the temperature T tends to zero. The ratio, p/C, C being the specific heat, is also shown to be proportional to T−1 in the low-temperature limit.
Direct detection of the Josephson current in Nb superconducting microbridges
Authors: Crozat P. , Vernet G. , Adde R.
Published: February 2003

The detection of the ac Josephson current in Nb microbridges with dimensions larger than the coherence length but smaller than the effective penetration depth is reported at frequencies between 1.7 and 180 GHz. Precise Josephson linewidth measurements are performed as a function of dc bias and frequency and the results are compared with the existing theories.
Effects of ion implantation on the structure of amorphous germanium
Authors: Graczyk J. F. , Chaudhari P.
Published: February 2003

We have investigated the structure of amorphous Ge films with 10-keV Ge74 ions. An analysis and subsequent comparison of the elastically scattered electron intensity from ion-implanted amorphous films with relaxed and unrelaxed model calculations using the Polk random network model suggests that ion implantation introduces isolated point defects (vacancies) in the network.
Infrared spectra of new acceptor levels in indium- or aluminum-doped silicon
Authors: Scott Walter
Published: February 2003

Infrared absorption measurements have verified the existence of shallower acceptor levels associated with both indium and aluminum in silicon. The new spectra correspond to effective-mass-like acceptors with optical ionization energies of 112.8±0.3 meV in indium-doped silicon and 56.3±0.3 meV in aluminum-doped silicon. The existence of the shallower acceptor level in aluminum-doped silicon has been further verified by Hall coefficient measurements.
Algorithm for measuring the internal quantum efficiency of individual injection lasers
Authors: Sommers H. S.
Published: February 2003

A new algorithm permits determination of the internal quantum efficiency ηi of individual lasers. Above threshold, the current is partitioned into a ’’coherent’’ component driving the lasing modes and the ’’noncoherent’’ remainder. Below threshold the current is known to grow as exp(qV/n0KT); the algorithm proposes that extrapolation of this equation into the lasing region measures the noncoherent remainder, enabling deduction of the coherent component and of its current derivative ηi. Measurements on five (AlGa)As double-heterojunction lasers cut from one wafer demonstrate the power of the new method. Comparison with band calculations of Stern shows that n0 originates in carrier degeneracy.
Quaternary alloy InxGa1−xAsyP1−y/InP photodetectors
Authors: Clawson A. R. , Lum W. Y. , McWilliams G. E. , Wieder H. H.
Published: February 2003

Acceptor-doped heteroepitaxial In0.84Ga0.16As0.34P0.66 layers grown on donor-doped InP substrates were used to construct self-filtering infrared detectors with a responsivity of 0.46 A/W at a wavelength λ=1.05 μm and a corresponding external quantum efficiency ηx=0.54.
Superradiant emission from electron-beam-excited POPOP vapor
Authors: Marowsky G. , Cordray R. , Tittel F. K. , Wilson W. L.
Published: February 2003

For the first time superradiant emission from an electron-beam-excited dye vapor has been observed. Temporal and spectral characteristics are described that confirm the presence of stimulated emission. The wavelength integrated net gain of an optimized POPOP dye vapor–buffer gas mixture is found to be 0.17 cm−1 at 1 Torr and 4 atm argon pressures for an absorbed power input of 40 MW into an active volume of 10 cm3. Under these conditions an estimate of the conversion efficiency from electronic energy to coherent light yields 5%. These results suggest that an efficient tunable electronically pumped dye vapor laser system is feasible.
Photoluminescence in the amorphous system SixC1−x
Authors: Engemann D. , Fischer R. , Knecht J.
Published: February 2003

We report the observation of visible photoluminescence in the amorphous SixC1−x(H) alloy system. The spectrum consists of two bands one of which shifts linearly with x. For x=0.4 the principle luminescence maximum lies at 2.1 eV.
Chemical vapor deposition of Nb3Ge on continuous stainless-steel tapes
Authors: Païdassi S. , Spitz J. , Besson J.
Published: February 2003

Superconducting films of Nb3Ge have been deposited by chemical vapor deposition on continuous stainless-steel tapes. Critical temperatures as high as 23.6 K (±0.2 K) have been obtained with relatively broad transitions (4–5 K). Critical current densities in magnetic fields of 180 kG are of the order of 105 A cm−2.
Integrated bistable optical devices
Authors: Smith P. W. , Kaminow I. P. , Maloney P. J. , Stulz L. W.
Published: February 2003

We describe several versions of an integrated bistable optical device fabricated with Ti in-diffused waveguides in LiNbO3. The ends of the LiNbO3 crystal are cleaved to form a Fabry-Perot resonator. These devices can be operated with as little as 1 pJ of optical switching energy.
Investigation of the radiative recombination process in CdSe (P-band) with 2-psec time resolution
Authors: Bryant S. F. , Dneprovskii V. S. , Sibbett W.
Published: February 2003

The characteristic delay, rise, and decay times of recombination radiation at high exciton densities (P∞-band) in CdSe monocrystal (77 K) were measured with 2-psec time resolution and found to be 34±6, 9±2, and 16±3 psec, respectively. The values of the rate constants of the exciton-exciton interaction and of the binding of free carriers into excitons were estimated.
Acousto-optic measurement of optical-field profiles in diffused LiNbO3 waveguides
Authors: Rowell N. L. , Normandin R. , Stegeman G. I.
Published: February 2003

Brillouin scattering from thermal longitudinal phonons in Ti in-diffused LiNbO3 waveguides is shown to provide a direct measurement of the optical-field profiles and the velocity of sound in the in-diffused region.
Annealing of ion-implanted silicon by an incoherent light pulse
Authors: Bomke H. A. , Berkowitz H. L. , Harmatz M. , Kronenberg S. , Lux R.
Published: February 2003

Annealing of boron-implanted silicon by a single 15-μsec pulse from a flash lamp has been observed. The required energy density was 27 J/cm2 incident on the silicon. Electrical activity of boron was comparable to that in thermally annealed samples.
Deuterium enrichment by cw CO2 laser-induced reaction of methane
Authors: Hsu D. S. Y. , Manuccia T. J.
Published: February 2003

A cw CO2 laser is used to vibrationally excite CH2D2. Intentional VT deactivation competes with interisotope VV transfer and prepares a sample of gas in which the CH2D2 is excited while the CH4 remains unexcited on a steady-state basis. Subsequent reaction of this mixture with chlorine atoms and molecules forms a stable product, deuterated methyl chloride, enriched in deuterium by up to 72%. Extension to the CH3D system will be discussed. A conservative estimate of the energy requirement for a commercial facility (natural abundance feed) based on the latter system gives a value within a factor of 4 of that required by the currently used H2O/H2S commercial process.
Phase-locked semiconductor laser array
Authors: Scifres D. R. , Burnham R. D. , Streifer W.
Published: February 2003

Five optically coupled narrow stripe (3.5 μm) GaAs/GaAlAs semiconductor lasers on 8-μm centers are operated as a spatially coherent phase-locked laser array. Output beams with less than 2° divergence are observed up to 60 mW/facet output with a quantum efficiency of greater than 25%/facet. Significant nonlinearities do not appear until well over 100 mW/facet output.
An acoustic SAW/CCD buffer memory device
Authors: Smythe D. L. , Ralston R. W. , Burke B. E. , Stern E.
Published: February 2003

A SAW piezoelectric delay line has been integrated with a silicon charge-coupled shift register device (CCD) across a 300-nm gap to produce a fast-in slow-out buffer memory. A prototype with an input bandwidth of 40 MHz centered around 107 MHz, an input signal duration time of 3.5 μs, and an output clock rate of 100 kHz has been fabricated and tested. The basic configuration of this SAW/CCD consists of a lithium niobate (LiNbO3) delay line, in close proximity to an array of 300 sampling fingers connected to a 300-stage buried-channel CCD on a p-type silicon susbtrate. The output of the CCD retains both amplitude and phase of the input signal.
Schottky-barrier height of iridium silicide
Authors: Ohdomari I. , Tu K. N. , d’Heurle F. M. , Kuan T. S. , Petersson S.
Published: February 2003

Iridium silicides have been prepared by annealing Ir films on (100) - and (111) -oriented Si from 300 to 500 °C. Phase identification was performed by both x-ray and electron diffractions, and Schottky-barrier height by current-voltage measurements. The silicide IrSi has been found to have a barrier height of 0.93 eV, which is the highest among all the silicides measured. The high value leads us to conclude that the silicide does not follow the linear relation which exists between barrier height and heat of formation of most other silicides.
Properties of optical waveguides formed by thermal migration of thallium ions in glass
Authors: Hafich M. , Chen D. , Huber J.
Published: February 2003

A simple process is presented for fabricating channel waveguides by a thallium-ion diffusion technique. The thallium diffusion coefficient is estimated to be 2×10−12 cm2/sec at 400 °C. Effective mode index measurements show a complementary error function index profile in the waveguide. Waveguide losses are measured to be −0.60 dB/cm. A passive component of optical communications systems, a star coupler, is fabricated using the thallium-ion exchange process.
Characteristic x-ray spectra of sodium and magnesium measured at room temperature using mercuric iodide detectors
Authors: Dabrowski Andrzej J. , Huth Gerald C. , Singh Manbir , Economou Thanasis E. , Turkevich Anthony L.
Published: February 2003

Mercuric iodide detectors, operating at room temperature with the FET of the first stage of amplification cooled with a two-stage Peltier element, have been used to detect low-energy x rays from light elements excited by 2.0- and 6.1-MeV α particles. X-ray lines from Na (1.04 keV) and Mg (1.25 keV) have been seen for the first time with room-temperature energy-dispersive detectors. A resolution of 390 eV at 1.25 keV was obtained. Further improvement of the resolution is believed to be achievable. However, even the present characteristics are adequate for many applications in x-ray fluorescence and elemental analysis. Several such possible applications are suggested.
Gain spectrum of a pulsed laser-pumped submillimeter laser
Authors: Drozdowicz Z. , Lax B. , Temkin R. J.
Published: February 2003

The gain spectrum of a pulsed submillimeter (SMM) laser amplifier has been determined for the first time using single-mode pump and submillimeter laser oscillators. The gain of a 385-μm D2O laser amplifier was measured as a function of CO2 laser pump power, D2O laser oscillator power, polarization, and D2O gas pressure. The use of single-mode lasers permits a direct comparison with theory. Comparison with a theory which takes into account two-photon contributions to the gain yields good qualitative agreement, in that theory accurately predicts the shape of the gain spectrum, including ac Stark effects and the dependence of the gain on polarization, but not the absolute magnitude of the gain.
High-temperature superconducting tape via the amorphous state
Authors: Tsuei C. C.
Published: February 2003

A novel approach to preparing ductile high-Tc and high-Hc2 superconducting composite tape via the amorphous state is described. This new process, successfully applied to ’’β-W’’ Nb3Ge and V3Si, makes full use of the superior mechanical properties characteristic of the amorphous metallic state. Both of these high-Tc materials are difficult to fabricate into tape or wire by conventional techniques.
An alternative marker experiment in the formation of Mo and W silicides
Authors: Baglin J. , d’Heurle F. , Petersson S.
Published: February 2003

A novel diffusion ’’marker’’ has been used in the backscattering study of the formation of Mo and W silicide films. Because of their closely similar crystallographic and chemical characteristics, Mo and W may be regarded as equivalent atoms in a diffusion process. Hence, in the formation of WSi2 and MoSi2 by interaction of a bilayer film of W+Mo with substrate Si, the interface between the W and Mo (observable by backscattering) becomes a ’’marker’’ to permit identification of the moving species (Si at T<1000 °C).
Miniature Nd-pentaphosphate laser with bonded mirrors side pumped with low-current-density LED’s
Authors: Budin J.-P. , Neubauer M. , Rondot M.
Published: February 2003

A laser made of a 1-cm-long Nd0.75La0.25P5O14 crystal with bonded mirrors has been side pumped with two arrays of light-emitting Al0.1Ga0.9As planar diodes in a double cylindrical-elliptical cavity. Pulsed operation (0.6 ms) is obtained at −13.5 °C, and cw lasing at −49 °C, with LED current densities of 700 and 270 A cm−2, respectively.
New electrothermo-optic effect in a certain smectic liquid crystal with a pleochroic dye added
Authors: Tani C. , Ueno T.
Published: February 2003

A new electrothermo-optic effect is described in a certain smectic liquid crystal with a pleochroic dye added. The thermally induced optical storage state in this mode consists of a mosaic texture. It does not show light scattering but has excellent coloration. The erasure of this state is made by the use of a field-assisted thermal process.
Analog read-only memory using gadolinium molybdate
Authors: Lemons R. A. , Geary J. M. , Coldren L. A. , Mattes H. G.
Published: February 2003

In ferroelectric gadolinium molybdate a stable planar domain wall can be swept through the crystal by applying a voltage along the polar axis. The resulting polarization current can be used to read out analog information stored as a waveform pattern in the electrodes. Using a differential detection scheme, we have demonstrated the reproduction of 4 sec of typical speech stored with a density of 50 sec of speech per cm2.
Direct determination of symmetry of Cr ions in semi-insulating GaAs substrates through anisotropic ballistic-phonon propagation and attenuation
Authors: Narayanamurti V. , Chin M. A. , Logan R. A.
Published: February 2003

We report ballistic phonon experiments in semi-insulating GaAs as a function of polarization and propagation direction and of the concentration of chromium in the crystal. The data provide direct evidence for a tetragonally distorted site symmetry of the Cr ions and a ground-state splitting at ∼14 K.
Gap-coupled InSb/LiNbO3 acoustoelectric convolver operating at 77 K
Authors: Leonberger F. J. , Ralston R. W. , Reible S. A.
Published: February 2003

A gap-coupled InSb/LiNbO3 acoustoelectric convolver has been fabricated and tested at 77 K. The results suggest the possibility of using a similar structure with a high-density InSb diode array as an acoustically scanned infrared imaging device. Measurements indicate that near optimum bias, the convolution efficiency was −63 dBm, the convolution output was uniform along the device length to within 1.5 dB, the insertion loss was 26 dB, the 1-dB compression point occurred at 18 dBm power input, and the efficiency was constant to ⩽ 3 dB over the range 66–70 MHz.
The Ga0.47In0.53As homojunction photodiode—A new avalanche photodetector in the near infrared between 1.0 and 1.6 μm
Authors: Pearsall T. P. , Papuchon M.
Published: February 2003

A new p-n photodetector operating at room temperature and sensitive in the near infrared for wavelengths as long as 1.6 μm has been made from Ga0.47In0.53As grown lattice matched on InP substrates by LPE. These detectors display avalanche gain and dark current as low as 2×10−9 A. Measurements of the speed of response at 1.06 μm have shown a detector response time as fast as 250 psec.
Josephson properties of Nb3Sn/Pb tunnel junctions
Authors: Howard R. E. , Rudman D. A. , Beasley M. R.
Published: February 2003

The Josephson properties of Nb3Sn/Pb tunnel junctions formed on electron-beam-deposited Nb3Sn are reported. The junctions are found to have large gaps, low leakage, and a much lower specific capacitance than Josephson junctions incorporating Nb base electrodes.
Elasto-optical technique for measurement of stress at surfaces
Authors: Miller Arthur
Published: February 2003

A nondestructive elasto-optical method is demonstrated for the measurement of absolute stress near the surfaces of transparent objects that have at least slight convex curvature. The method is based on the ability of electromagnetic waves to propagate along such surfaces, even though there is no high-index guiding layer. A small but appreciable correction term is derived that is due to the difference in effective refractive indices between TE and TM modes.
TTE suppressed surface acoustic wave filter
Authors: Tsukamoto Masahide
Published: February 2003

A new design of SAW filters having an inclined and tapered three transducer (ITTT) configuration is effective for the suppression of the triple-transit (TTE) caused by the regeneration of an surface acoustic wave. In the ITTT configuration, the electrode fingers of the transducers are not parallel with each other but are tapered, and further, each of the outer output transducers is inclined with respect to the central input transducer. A video i.f. filter for TV having the ITTT configuration was fabricated using a piezoelectric ceramic substrate. The filter exhibited an insertion loss of 9.6 dB and ripple in the group delay of less than 50 nsec.
Nonlinear dependence of cathodoluminescence on activator concentrations
Authors: Ozawa Lyuji
Published: February 2003

It has been demonstrated that the concentration-dependence curve of cathodoluminescence provides us with a new tool for studying the statistical results of the motion of the mobile carriers in crystals. The experimental results reveal the nonlinear dependence on the activator concentration, suggesting an unknown motion of the mobile carriers in the crystals.
Grain-boundary edge passivation of GaAs films by selective anodization
Authors: Pande K. P. , Hsu Y-S. , Borrego J. M. , Ghandhi S. K.
Published: February 2003

Solar cells built on polycrystalline gallium arsenide usually have very leaky reverse characteristics and, consequently, low open-circuit voltage. These problems arise from the effect of the Schottky diode made on the grain boundary, which behaves like n+-material. This diode shunts the active Schottky solar cell and deteriorates its performance characteristics. In this letter we describe the use of selective-anodization techniques to provide an insulating barrier over the edge of the grain boundary in order to passivate it. Leakage current reduction of 5–6 decades has been achieved by this method, with both aqueous and nonaqueous anodization methods.
Closed-tube control of out-diffusion during fabrication of optical waveguides in LiNbO3
Authors: Esdaile R. J.
Published: February 2003

The control of both O2 and Li2O out-diffusion during fabrication of optical waveguides by the in-diffusion of titanium into LiNbO3 is important. A simple technique, using a sealed system under conditions approaching equilibrium, has been developed which does allow effective control of this problem.
An application of Wiener filtering to nondestructive evaluation
Authors: Murakami Y. , Khuri-Yakub B. T. , Kino G. S. , Richardson J. M. , Evans A. G.
Published: February 2003

The inverse problem of defect characterization is carried out by comparing theoretical and experimental return echo pulses. Acoustic echo signals of the order of 2 ns long are digitized and fed into a digital computer. A Wiener filter is designed to match the transducer response, so the impulse response of the system approaches a δ function. Experimental results on defects in Si3N4 ceramics are presented which demonstrate the power of such a technique for defect characterization.
Parametric amplification and generation of surface acoustic waves on a monolithic MIS structure
Authors: Minagawa S. , Kugaya T. , Tsubouchi K. , Mikoshiba N.
Published: February 2003

We report on a new surface-acoustic-wave (SAW) amplifier and generator on a monolithic MIS structure with a uniform pump electrode. The gain for the forward SAW and the generation of the backward SAW have been observed in an Al/ZnO/SiO2/Si structure. Using the same structure, we observed for the first time the parametric generation of SAW of 222 MHz by the uniform pumping, even if there is no signal input.
Electric field tuning of second-harmonic generation in a three-dimensional LiNbO3 optical waveguide
Authors: Uesugi Naoshi , Daikoku Kazuhiro , Kubota Katsutoshi
Published: February 2003

Electric-field-tuning characteristics of second-harmonic generation in a three-dimensional Ti in-diffused LiNbO3 optical waveguide are reported. It is experimentally revealed that the phase-matching condition for second-harmonic generation can be achieved with low voltage applied across electrodes. For the present optical waveguide, a 1 °C temperature change is equivalent to about 13 V in phase matching, which agrees well with the calculated value. Rapid tuning or switching of parametric interactions in the LiNbO3 waveguide is expected with a low applied voltage.
A ZnSe-ZnTe amorphous heterojunction
Authors: Moore C. J. , Brodie D. E.
Published: February 2003

An all-amorphous thin-film p-n heterojunction has been fabricated and is described. The films were prepared by vacuum deposition. An analysis of the I-V characteristics suggests that the mechanisms are more complicated than those represented by the standard diode equation.
Contrast and resolution of SEM charge-collection images of dislocations
Authors: Donolato C.
Published: February 2003

Image profiles obtained in the scanning electron microscope operating in the charge-collection mode are calculated for a dislocation perpendicular to a surface barrier. The image resolution is not limited by the minority-carrier diffusion length in the semiconductor, but only determined by the generation volume, in agreement with experiment. The contrast characteristics of a dislocation differ from those of a localized defect, leading to a practical method for distinguishing the two types of imperfections.
Reductions in static fatigue of silica fibers by hermetic jacketing
Authors: Pinnow D. A. , Robertson G. D. , Wysocki J. A.
Published: February 2003

The lifetime of stressed silica fibers is normally limited by moisture-enhanced stress corrosion cracking known as static fatigue. We have developed a metal-jacketing technique that provides a hermetic protection of the glass fiber surface. Fibers protected in this fashion appear to be immune to normal static fatigue effects. Lifetimes of stressed silica fibers with hermetic jackets have been observed to be more than five orders of magnitude longer than those of conventional plastic-coated fibers.
Low-loss propagation and polarization rotation in twisted infrared metal waveguides
Authors: Garmire E. , McMahon T. , Bass M.
Published: February 2003

Low-loss propagation of 10.6-μm light has been demonstrated in hollow metal waveguides of rectangular cross section that undergo axial twists. These twisted waveguides can serve as efficient infrared polarization rotators, where greater than 90% transmission has been achieved at 10.6 μm for a 90° rotation. In addition, transmission of more than 200 W cw through flexible waveguides is reported here, confirming that these waveguides are potentially useful for steering high-power infrared light beams.
Microstructure dependence of the optical properties of solar-absorbing black chrome
Authors: Ignatiev A. , O’Neill P. , Doland C. , Zajac G.
Published: February 2003

The surface microstructure and chemical constituency of solar-absorbing black chrome films have been studied by scanning electron microscopy (SEM), x-ray photoemission spectroscopy (XPS), and sputter depth-profiling techniques. The films have been determined to consist of a top layer of small (∼400 Å) Cr2O3 particles with one or two sublayers of larger (∼1000 Å) closely packed chromium particles. In addition, it has been shown that the optical response of the particulate black chrome films is significantly determined by the microstructure of the films.
Transverse modes in gap-coupled surface-wave devices
Authors: Reible S. A.
Published: February 2003

The support structure used to maintain a uniform air gap in separated-media acoustoelectric devices can cause considerable distortion of the acoustic-beam profiles. These distortions, which include the decomposition of the incident acoustic beam into multiple waveguide modes, have a detrimental effect on the efficiency and frequency response of the devices. Experimental observations have led to a simple rail array which minimizes the undesirable effects of the support structure.
Measurement of minority-carrier lifetime in GaAs using the transient response of MOS capacitors
Authors: Vitale G. , Crisman E. E. , Loferski J. J. , Roessler B.
Published: February 2003

The minority-carrier generation lifetime has been measured in GaAs by observing the transient capacitance that occurs when an MOS is switched from accumulation to deep depletion. Application of this technique requires the fabrication of an MOS that shows inversion; this has been done by growing a native GaAs oxide with plasma oxidation. Preliminary results are reported on both lifetime and surface recombination velocity in p-type GaAs.