bluuebunny/crossref_metadata_2025 huggingface dataset:
THE RUBY LASER: PUMPED BY A PULSED ARGON ION LASER
Authors: Birnbaum Milton , Fincher Curtis L.
Published: January 2004

A ruby laser with a pulsed argon ion laser as a pump was constructed and operated at 77° and 300°K. Threshold for oscillation was ∼13 mJ. A unique type of Q-switched operation was observed that produced pulses of ∼15 nsec at 300°K and ∼6 nsec at 77°K.
EFFECT OF TEMPERATURE ON SURFACE CHARGES CAUSED BY AN INCIDENT ELECTRON BEAM ON A METALLIC SURFACE
Authors: Petit-Clerc Y. , Carette J.-D.
Published: January 2004

Measurements have been made of the behavior of surface charges caused by an electron bombardment, with an increase in temperature. At 200°C surface charges are still present although reduced by a factor 4. At this temperature the life of the surface charges is much shorter than at room temperature.
VOLTAGE RESOLUTION OF THE ELECTRON MIRROR
Authors: Barnett M. E.
Published: January 2004

The least detectable amplitude of surface potential variation is derived for the electron mirror method of surface imaging. It is shown that it can be very much smaller than the thermal energy spread in the imaging beam.
TEMPERATURE DEPENDENCE OF THE MICROWAVE DIELECTRIC CONSTANT OF THE GaAs LATTICE
Authors: Champlin Keith S. , Glover Gary H.
Published: January 2004

The relative dielectric constant εr of high-resistivity GaAs has been measured at 70.243 GHz as a function of temperature between 100 and 300°K. The measuring technique utilized a circular E field (TE°01) mode reflection-coefficient bridge. Estimated relative and absolute accuracies of the measurements are ±0.2% and ±0.5%, respectively. The results are found to fit the equation εr(T) = εr(0){1 + αT} where εr(0) = 12.73 ±.07 and α = (1.2 ± 0.1) × 10−4. At room temperature (295°K) the relative permittivity is εr = 13.18 ±.07.
INTERVALLEY TRANSFER AND MICROWAVE CURRENT OSCILLATIONS IN STRAINED n-TYPE GERMANIUM
Authors: Smith John E.
Published: January 2004

Microwave current oscillations have been observed in uniaxially compressed n-type germanium in high electric field. For the configuration where the current is along the [112̄] crystal axis, and the strain along the [111] direction, the effect is present at 27°, 77°, and 300°K. At 27°K, the oscillations begin at stress of 1500 kg/cm2; the threshold electric field has a minimum of 270 V/cm at a stress of 5000 kg/cm2. These values are higher at higher temperatures. The phenomenon is believed to be due to the existence of a region of bulk negative differential conductivity which results from intervalley transfer of electrons between the stress-split 〈111〉 valleys of the conduction band.
ULTRASONIC REFLECTIVITY AND SURFACE WAVE PHENOMENA ON SURFACES OF COPPER SINGLE CRYSTALS
Authors: Rollins Fred R. , Lim T. C. , Farnell G. W.
Published: January 2004

The phase velocities of surface waves on low index surfaces of single-crystal copper have been determined by an ultrasonic reflection technique and found to be in excellent agreement with theoretical values. Variations in reflectivity have been related to both generalized surface waves and pseudo-surface waves.
DOPING OF SILICON BY ION IMPLANTATION
Authors: Itoh Tadatsugu , Inada Taroh , Kanekawa Kiyoshi
Published: January 2004

Radiation damages created in silicon single crystals bombarded with 10-keV aluminum ions were examined by means of electron diffraction method. A deep penetration of aluminum ion in silicon was observed, extending to 0.58 μ. This penetration was depressed by removing the bombarded surface layer about 800 Å in thickness before annealing. From these results, we interpret the deep penetration as a radiation enhanced diffusion effect.
RAMAN LINEWIDTHS FOR STIMULATED THRESHOLD AND GAIN CALCULATIONS
Authors: Clements W. R. L. , Stoicheff B. P.
Published: January 2004

Linewidths in the normal Raman spectra of several liquids of interest in stimulated Raman scattering have been measured including carbon disulfide, benzene, toluene, oxygen, and nitrogen. The spectra were excited with 6328-Å radiation from a He-Ne laser and examined with a pressure-scanned Fabry-Perot interferometer.
HOT-CARRIER MICROWAVE HARMONIC GENERATION
Authors: Fisher P. David
Published: January 2004

Microwave second-harmonic generation is observed in germanium when a microwave power density gradient exists within the sample. This second-harmonic thermoelectric voltage is proportional to the incident microwave power for low power levels and is found to begin to saturate as the power level approaches 1 mW. This voltage could be utilized to directly measure the energy relaxation time of free charge carriers.
AMPLIFICATION OF ULTRASONIC WAVES UNDER DC OPERATING CONDITION IN InSb UNDER TRANSVERSE MAGNETIC FIELD
Authors: Hayakawa Hisao , Kikuchi Makoto
Published: January 2004

Amplification of ultrasonic waves at 225 MHz up to 20 dB has been achieved by the dc operation in n-InSb under the transverse magnetic field at 77°K. If we assume that dc and ac mobilities have different dependence on the magnetic field, most of the characteristic features of the observed results are well explained.
THE OPTICAL DETECTION OF STIMULATED EMISSION IN CN AT 20-CM WAVELENGTH
Authors: Evenson Kenneth M.
Published: January 2004

Six of the seven allowed electric dipole transitions between the hyperfine levels of the J = 7/2 lambda doublet in the 10th vibrational level of the A2π3/2 state of CN were observed. The transitions at frequencies between 1580 and 1650 MHz occur between the more populated negative parity levels and the positive parity levels. The stimulated emission was detected by measuring an increase in the intensity of the B2Σ+ → X2Σ+(0, 0) violet band of CN near 3875 Å.
EXPERIMENTAL EVIDENCE FOR INTERSTITIAL In AND Tl IN ION-IMPLANTED SILICON
Authors: Davies J. A. , Eriksson L. , Mayer J. W.
Published: January 2004

Using the channeling technique for locating foreign atoms in crystals, we have obtained direct experimental evidence of an irreversible motion of In and Tl atoms from substitutional to interstitial sites during the annealing of ion-implanted silicon samples. Preliminary Hall measurements indicate that a corresponding transition from p- to n-type behavior also occurs in the same temperature region — viz. 525–575°C. Implantation conditions were 1–3 × 1014 ions/cm2 at 40 keV, with the substrate at 350–450°C to prevent lattice disorder from accumulating.
MEMORY BEHAVIOR OF AN MNS CAPACITOR
Authors: Pao Henry C. , O'Connell M.
Published: January 2004

The memory behavior of an MNS capacitor caused by high voltage pulses is described. The instantaneous charge transfer during pulsing is measured and analyzed, and the results compared favorably with those from the C-V measurement. With this technique the charge transfer was found to be essentially insensitive to temperature up to 300°C. By means of step-etch tests the stored charge was found to be located within 100 Å of the interface. Tunneling is believed to be the conduction mechanism.
REDUCTION IN MECHANICAL STRENGTH OF COPPER BY THE PRESENCE OF A THIN EPITAXIAL OVERGROWTH OF NICKEL
Authors: Ruddle G. E. , Wilsdorf H. G. F.
Published: January 2004

Thin overgrowths of nickel were epitaxially formed by electrodeposition on substrate single crystals of copper having specific orientation and geometry. The prepared composite crystals were deformed in tension to small strains and found to have yield stresses significantly lower than for unplated copper crystals. Supported by evidence from replica-electron microscopic examination of the surface slip structures, it is proposed that the elastic condition of the low interfacial misfit formed by the thin nickel overgrowth on copper promotes activation of surface dislocation sources.
OBSERVATION OF PICOSECOND PULSES FROM A Nd:YAG LASER
Authors: Bass M. , Woodward D.
Published: January 2004

Ultrashort pulses are observed in the output of a Pockel's cell Q-switched, pulsed Nd:YAG laser. This result suggests that self-locking effects occur in Nd:YAG lasers and that the output of such lasers may, in general, be composed of many picosecond pulses.
CURRENT-VOLTAGE CHARACTERISTICS OF JOSEPHSON JUNCTIONS
Authors: Stewart W. C.
Published: January 2004

A model for superconducting Josephson junctions analogous to the driven simple pendulum with damping gives dc I-V curves displaying hysteresis for light damping. Excess current and negative dynamic resistance can be obtained with heavy damping.
EFFECTS OF ELECTRIC AND MAGNETIC FIELDS ON THE STRUCTURE OF CHOLESTERIC LIQUID CRYSTALS
Authors: Meyer Robert B.
Published: January 2004

Electric or magnetic fields acting on the anisotropy of the electric or magnetic susceptibility exert torques within a liquid crystal which may compete with the elastic torques determining its internal structure. A general method is presented for calculating the structural changes thus produced. Two examples are given, and the field strength for the effects is estimated to be 105 V/cm or 105 G. Two experiments are suggested to test the theory.
TRANSVERSE NEGATIVE DIFFERENTIAL MOBILITIES FOR HOT ELECTRONS AND DOMAIN FORMATION IN GERMANIUM
Authors: Shyam M. , Kroemer H.
Published: January 2004

In n-type germanium samples biased with a field in the range 4–10 kV/cm along (110) direction, the differential mobility along the (001) direction is found to be negative. Such transverse negative mobilities give rise to the formation of electrically polarized domains at right angles to the drift velocity of electrons. A brief discussion of the origin of negative transverse mobility is presented.
PHOTOSENSITIVITY IN MONOCRYSTALLINE PbS FILMS
Authors: Riedl H. R. , Schoolar R. B.
Published: January 2004

Monocrystalline films of lead sulfide have been made photosensitive by baking in air or sulfur vapor. It is shown that the baking process formed narrow lines of material which are more p type than the host film. These lines, oriented along [100] and [010] directions, are responsible for the observed photosensitivity.
SURFACE-STATE RELATED l/f NOISE IN p-n JUNCTIONS AND MOS TRANSISTORS
Authors: Hsu S. T. , Fitzgerald D. J. , Grove A. S.
Published: January 2004

It is shown experimentally that l/f noise both in silicon p-n junctions and in MOS transistors can be increased by the introduction of a particular type of surface state. The additional noise power is proportional to the density of these states. The surface states are introduced by the application of an electric field across the oxide at elevated temperatures (e.g., ∼300°C); they are relatively ineffective as surface recombination centers.
INFLUENCE OF XENON ON CO2 LASER PLASMAS
Authors: Bletzinger P. , Garscadden A.
Published: January 2004

Measurements are reported showing the influence of xenon on the discharge properties of CO2 lasers. Small admixtures of xenon lower the electron temperature considerably and it is possible to operate the CO2 laser without nitrogen and with little decrease in output power for low flow rates or sealed-off operation. The influence of added CO is reported briefly. It is proposed that direct electronic excitation to the vibrational levels of CO and consequent vibrational energy transfer from the CO (v = 1) to the CO2 upper laser level is the most important mechanism when N2 is absent.
NONLINEAR ABSORPTION OF LIGHT. POSITIVE AND NEGATIVE SATURATION EFFECTS IN THE SAME ABSORBER
Authors: Giuliano C. R. , Hess L. D.
Published: January 2004

The optical transmission of platinum dithizonate dissolved in CCl4 was measured as a function of intensity at 6943 Å. When a 35-nsec pulse is used for excitation the transmission increases from its low-level value at a power density of 0.1 MW/cm2, goes through a maximum at 10 MW/cm2 and then decreases to its low-level value at 80 MW/cm2. This material functions effectively as a passive Q switch for ruby and may provide power stabilization as well. A long-lived cumulative bleaching effect is produced when the output from a non-Q-spoiled laser is used for excitation. The transmission behavior of this system at all intensities is discussed in terms of a generalized kinetic mechanism.
A HOLOGRAPHIC MOTION PICTURE FILM WITH CONSTANT VELOCITY TRANSPORT
Authors: De Bitetto D. J.
Published: January 2004

A direct application of the recently published technique of eliminating vertical parallax from holograms is that it permits reconstruction of holographic motion pictures with a constant-velocity film-strip motion. We have demonstrated this, both for three-dimensional holographic movie viewing and for two-dimensional holographic movie projection.
PULSE RESPONSE OF ELECTRO-OPTIC MODULATORS AND PHOTOCONDUCTIVE DETECTORS AT 10.6 μ
Authors: Bridges T. J. , Chang T. Y. , Cheo P. K.
Published: January 2004

Subnanosecond rise time pulses of 10.6-μ radiation obtained with a GaAs electro-optic modulator have been used to measure the time response of Cu:Sb, Cu, Hg, and Au doped germanium photoconductive detectors. Ge:Cu:Sb and Ge:Cu detectors yielded the fastest response, ∼1-nsec rise time (10% to 90%) with a 50-Ω load, which was circuit limited. Actual material time response of the Ge:Cu:Sb and Ge:Cu detectors and also of the GaAs modulator were determined to be less than 0.5 nsec. No saturation was observed for the Ge:Cu:Sb detector for peak input powers up to 20 W.
DAMAGE IN DOUBLE-POSITIONED GOLD FILMS BOMBARDED WITH HELIUM IONS
Authors: Nordén H. , Högberg G. , Andreen C. J.
Published: January 2004

Double-positioned gold films of (111) orientation are used in a study of the reduction in radiation damage due to channeling.
TYPE CONVERSION AND p-n JUNCTIONS IN n-CdTe PRODUCED BY ION IMPLANTATION
Authors: Donnelly J. P. , Foyt A. G. , Hinkley E. D. , Lindley W. T. , Dimmock J. O.
Published: January 2004

Type conversion and p-n junctions have been produced by the implantation of 400-keV As+ ions into n-CdTe. In forward bias, the junctions emit bandgap infrared radiation at room temperature.
CONTINUOUS 0.532-μ SOLID-STATE SOURCE USING Ba2NaNb5O15
Authors: Geusic J. E. , Levinstein H. J. , Singh S. , Smith R. G. , Van Uitert L. G.
Published: January 2004

A continuous 0.532-μ solid-state source utilizing the nonlinear material Ba2NaNb5O15 inside the cavity of a 1.064-μ YAlG:Nd laser has generated 1.1 W of coherent green power. This represents 100% conversion to the green of the available infrared radiation from the YAlG:Nd laser utilized.
CONTINUOUS OPTICAL PARAMETRIC OSCILLATION IN Ba2NaNb5O15
Authors: Smith R. G. , Geusic J. E. , Levinstein H. J. , Rubin J. J. , Singh S. , Van Uitert L. G.
Published: January 2004

A tunable, optical parametric oscillator using a continuous pump is reported. The threshold was measured to be 45 mW of multimode power at .532 μ. The efficiency was found to be 1% with 300 mW of pump power.
OBSERVATION OF GROWING CARRIER WAVES IN INDIUM ANTIMONIDE
Authors: Burke B. E. , Kino G. S.
Published: January 2004

Measurements of the phase velocity and growth rate of carrier waves in near-intrinsic InSb are presented. The frequency range is from 10 to 40 MHz and a transverse magnetic of about 2 kG is required. The phase velocity of the wave agrees with predictions of previous theories, but the large growth rates suggest a new type of two-stream interaction involving surface waves suggested by Kino.
RECTIFYING Te–Se–Cd STRUCTURES USING A SELENIUM SINGLE-CRYSTAL FILM
Authors: Champness C. H. , Griffiths C.H. , Sang H.
Published: January 2004

Rectifying Te–Se–Cd structures have been prepared in the laboratory using (101̄0) and (0001) selenium single-crystal films. In the forward direction the current density below 1 V follows the rectifier equation for a heterojunction and above 1 V it approaches a quadratic voltage dependence. In the latter voltage region a conventional selenium rectifier, however, shows a linear dependence.
PRODUCTION OF BLAZED HOLOGRAMS
Authors: Sheridon Nicholas K.
Published: January 2004

The concept of the blazed hologram as a special case of the Denisyuk hologram is discussed. Experimental production of blazed holograms is described. Blazed diffraction gratings, a form of blazed hologram, have been produced with 73% of the diffracted light concentrated in one first-order maximum.
GAUSSIAN BEAMS FROM GaAs JUNCTION LASERS
Authors: Zachos T. H.
Published: January 2004

Gaussian beams have been obtained from a GaAs junction laser operating in conjunction with a microscope objective and a slit. The laser mirror illumination, as viewed in the image plane of the objective, is asymmetric perpendicular to the junction plane and consists of a primary intensity maximum along with several weaker secondary peaks. The slit, placed in the image plane, suppresses the secondary peaks thereby eliminating their effects in the diffraction field. The isolated primary maximum is approximately Gaussian shaped and the radiation emanating from the slit retains its Gaussian profile as it propagates into the far-field region.
THE EFFECT OF HYDROSTATIC PRESSURE ON CURRENT OSCILLATIONS IN n-Ge
Authors: Melz Peter J. , McGroddy James C.
Published: January 2004

High pressure measurements made on the current oscillations in n-Ge show an increase in threshold field and decrease in the amplitude and range of the oscillations with increased pressure. No oscillations are observed above approximately 4 kbars. These results are consistent with the existence of an intraband bulk negative differential conductivity.
ATTENUATION OF ELASTIC SURFACE WAVES IN QUARTZ AT FREQUENCIES OF 316 MHz AND 1047 MHz
Authors: Salzmann E. , Plieninger T. , Dransfeld K.
Published: January 2004

The attenuation of elastic surface waves in crystalline quartz at frequencies of 316 MHz and 1047 MHz has been measured as a function of temperature between 4.2°K and 300°K. At temperatures below 30°K the absorption per cm was found to follow a T4 law with an approximately linear frequency dependence. At the higher temperatures the absorption varied as ω2 and was independent of temperature. The surface waves were detected by direct piezoelectric transduction and by a new optical method.
THE METALLOGRAPHIC STRUCTURE OF CONTINUOUS VAPOR DEPOSITED SiC FILAMENTS
Authors: Adler R. P. I. , McCandless L. C. , Heffelfinger R. E. , Lanstrom D. K.
Published: January 2004

Although the microstructure of continuous SiC filaments can be controlled by regulating the deposition temperature, the relative concentrations of the reactant gases, and the number of plating chambers, additional microstructural features present in the filaments are due to inherent, localized thermal effects in the plating chambers.
ANISOTROPIC THERMAL CONDUCTIVITY OF ELECTRON-IRRADIATED CdS
Authors: Vook Frederick L.
Published: January 2004

Measurements of the low temperature thermal conductivity of electron-irradiated CdS were made on irradiation and annealing. The measurements show that primary defects move at temperatures as low as 35°K in CdS. After annealing above 60°K, an anisotropic thermal conductivity is developed which is attributed to the formation of anisotropic phonon scatterers. The preferred orientation of the anisotropic defects is along the c axis, and the equilibrium energy difference for reorientation is ∼1.5 × 10−3 eV.
DISLOCATION ENERGY LEVEL IN SILICON FROM DISLOCATION VELOCITY MEASUREMENTS
Authors: Patel J. R. , Frisch H. L.
Published: January 2004

The energy of the dislocation acceptor level in silicon has been determined from dislocation velocity measurements in n-doped silicon using a model proposed earlier, in which the velocity is proportional to the charge on a dislocation. The dislocation level Es = 1.2±.2 eV above the valence band lies close to the conduction band edge in silicon. The proximity of Es to the conduction band is consistent with the observation that p doping at levels as high as 8 × 1019 cm−3 of acceptors has little or no influence on dislocation velocity.
MICROWAVE SCATTERING FROM ANISOTROPIC PLASMA TURBULENCE
Authors: Granatstein V. L.
Published: January 2004

Microwaves are scattered from an under-dense turbulent plasma. The plasma fluctuations are induced by the strong flow of gas through a discharge tube. The variation of scattered power as a function of scattering angle and angle of incidence is shown to be consistent with the spectral content of the plasma fluctuations as resolved by electrostatic probes provided that the turbulence is anisotropic with thin eddies stretched along the flow axis. An independent check for the existence of this anisotropy is obtained by observing that the backscattered signal becomes increasingly depolarized as grazing incidence is approached.
X-RAY DYNAMICAL DIFFRACTION EFFECTS OF OXIDE FILMS ON SILICON SUBSTRATES
Authors: Patel J. R. , Kato Norio
Published: January 2004

X-ray dynamical diffraction effects due to thin oxide films on silicon substrates have been examined. Contraction of Pendellösung fringes have been observed in x-ray topographs, due to strains introduced by the oxide film. Using the dynamical theory of x rays in distorted crystals described in the following Letter, we have been able to compute the stress in the oxide from the position of the fringes introduced by distortion.
DYNAMIC SCATTERING IN NEMATIC LIQUID CRYSTALS
Authors: Heilmeier G. H. , Zanoni L. A. , Barton L. A.
Published: January 2004

A new electro-optic effect based on the disruptive effects of ion transport through certain classes of nematic liquid crystals is presented. The initially transparent liquid scatters light strongly (appears white) when subjected to fields of 5 × 103 V/cm. Reflective contrast ratios of better than 20:1 with efficiencies of 45% of the standard white have been obtained.
RECONSTRUCTION OF A THREE-DIMENSIONAL MICROSCOPIC SAMPLE USING HOLOGRAPHIC TECHNIQUES
Authors: Toth Louis , Collins Stuart A.
Published: January 2004

A three-dimensional microscopic sample is recorded holographically using a high numerical aperture but not necessarily perfect lens. The volume sample is reconstructed using the same lens and is viewed using an ordinary microscope. The technique claims a virtually aberration-free reconstruction image of a volume much larger than that observable with a single positioning of a high magnification objective.
EVIDENCE OF LONGITUDINAL MAGNETOELASTIC WAVES IN YIG RODS
Authors: de Santis P.
Published: January 2004

A magnetoelastic mode has been experimentally observed in an obliquely magnetized YIG rod under two port operation conditions.

It is interpreted to be due to axially propagating waves relative to the lower branch of the magnon-longitudinal phonon dispersion curve.
TIME DEPENDENT SPECTROSCOPY OF FLASHLAMP PUMPED DYE LASERS
Authors: Furumoto H. , Ceccon H.
Published: January 2004

Time-resolved emission spectra from flashlamp-pumped organic dye lasers were recorded with an image converter camera. The characteristics of several dyes are examined and compared. The rhodamine dyes showed uniform spectral output, but other dyes showed irregular time dependent spectral output.
FIELD-ENHANCED CONDUCTIVITY IN TiO2 (RUTILE)
Authors: Johnson O. W.
Published: January 2004

Previously published data on the conductivity changes induced in rutile (TiO2) by an applied field are reinterpreted in the light of new information on the behavior of donor impurities in this crystal. It is suggested that the large increase in conductivity which is usually observed is electronic in nature, and is due to an increase in H+ interstitial concentration. The H is introduced at the anode, probably by electrolysis of H2O, migrates through the crystal under the influence of the applied field, then is neutralized at the cathode and escapes from the crystal. Enhanced conductivity results when migration of H+ near the cathode is inhibited by Ti4+ interstitials, thus increasing H+ concentration in the bulk. Other possible mechanisms are considered.
TEMPORAL REFERENCE HOLOGRAPHY
Authors: Metherell A. F.
Published: January 2004

This paper describes a new form of acoustical and microwave holography which obviates the need for a real or electronically simulated reference wave. The use of linear (rather than square-law) detectors permits recording of the instantaneous non-time-averaged object wave potential within the acoustic or microwave cycle rather than the intensity of the sum of an object wave and a reference wave time-averaged over many cycles. The time at which the recording is made is the reference rather than a real or electronically simulated reference wave. To achieve the effect of a plane reference wave making an angle θ with the hologram plane, it is necessary to record the object wave potential instantaneously along a straight line on the hologram at the same time as the recording line is swept with velocity v across the plane in the direction perpendicular to the line. Then sinθ = a/v, where a is the speed of the acoustic or microwave radiation. The feasibility of this method is demonstrated by recording and reconstructing a 4.8-MHz temporal reference acoustical hologram made with a Sokolov ultrasonic camera system.
TRANSIENT GYROMAGNETIC BEHAVIOR OF BLOCH WALLS IN THIN MAGNETIC FILMS
Authors: Lin Y. S. , Chang H. , Tolaba J. H.
Published: January 2004

The transient gyromagnetic behavior of the one-dimensional 180° Bloch walls in thin films is analyzed based on the Landau-Lifshitz equation for distributed systems. The physical model of gyromagnetic spin motion in the wall is found adequate in explaining wall streaming (or worm motion). The key mechanism is the induction of a large transverse magnetostatic field resulting from discrepancy in switching speeds in the wall and the adjoining regions. The dependence of wall displacement on pulse shapes and film parameters is examined.
THE FIELD ION MICROSCOPY OF GOLD
Authors: Ast D. G. , Seidman D. N.
Published: January 2004

The phenomenon of hydrogen promotion of field evaporation has been applied to the problem of producing stable images of highly perfect gold FIM specimens. Well developed, stable end forms of gold specimens were obtained by first field evaporating the gold specimen in a 0.5% H2–He gas mixture, then removing the hydrogen gas, and finally imaging the surface in a 25% Ne–He gas mixture. The imaging temperature of the specimen was ∼ 16°K. Details of the experimental observations concerning hydrogen promotion of field evaporation, and the characteristics of the gold end form are reported.
RESISTANCE LIMITED CURRENTS IN SOLIDS WITH BLOCKING CONTACTS
Authors: Schmidlin F. W. , Roberts G. G. , Lakatos A. I.
Published: January 2004

The existing theory of electric conduction in solids fitted with blocking contacts has been modified to include the effect of a series resistance. Experimental current-voltage curves for trigonal Se with indium electrodes are reported which show the essential features predicted by our theoretical analysis.
SPATIAL RESOLUTION MEASUREMENTS IN UP-CONVERSION FROM 10.6 m TO THE VISIBLE
Authors: Warner J.
Published: January 2004

10.6-μm radiation from a pair of point sources at optical infinity has been mixed with collimated ruby-laser radiation in Proustite. The sum-frequency radiation at 6516 Å so produced was then focused with a camera lens to form a visible image of the infrared sources. With a pump-laser beam divergence of 1.2 mrad the minimum resolvable angular separation of the infrared sources was 15 mrad according to the Rayleigh criterion.
ENHANCED STRAIN AMPLITUDE DEPENDENCE OF INTERNAL FRICTION IN THE MIXED STATE OF NIOBIUM
Authors: Kramer Edward J. , Bauer Charles L.
Published: January 2004

Strain amplitude dependence of internal friction was measured as a function of the magnetic state in a niobium single crystal. An enhanced dependence is observed in the mixed state, which is attributed to compression and subsequent breakaway of fluxoids from moving dislocations.
EVOLUTION OF A Q-SWITCHED LASER PULSE FROM NOISE
Authors: Fleck J. A.
Published: January 2004

Q-switched laser emission is calculated using a fluctuating dipole model of spontaneous emission. The emission pattern for a broadband noise source is a complicated quasi-periodic train of short pulses.
SATURATED ABSORPTION BY NEON INSIDE A 6328 Å LASER WITH A MIXTURE OF NEON ISOTOPES IN ITS GAIN TUBE
Authors: Schweitzer Walter G.
Published: January 2004

In a saturated absorption experiment with neon in a 6328-Å He–Ne laser one can select a combination of isotopes of neon in the gain tube and the proper isotope in the loss tube so as to bring the maximum of the gain curve to the same frequency as that of the saturated absorption peak.
OPTICAL SATURATION IN LASER LIGHT SCATTERING
Authors: Kielich Stanislaw
Published: January 2004

Possibilities of observing light scattering from an intense laser beam, whose electric field in well-defined conditions can cause total orientation of the scattering microsystems, are investigated on the basis of a simple classical theory. This saturation of orientation affects the scattered light and should be accessible to measurement in solutions of macromolecules or colloidal particles by usual laser technique, whereas in molecular liquids it cannot be made apparent even if using the focused beam of a strong laser. The measurements under consideration are proposed as a novel and simple method of determining the sign of the optical anisotropy of macromolecules and colloidal particles.
EFFECTS OF RADIATION PRESSURE ON A LASER-PRODUCED PLASMA
Authors: Weichel Hugo , David C. D. , Avizonis P. V.
Published: January 2004

Four specific experimentally observed phenomena associated with a laser-produced carbon plasma in a vacuum are described. They are superheating of the target surface, a sharply defined and slightly indented leading boundary of the expanding plume, a density precursor in the expanding plume, and the merging of the electron and ion temperatures at very high laser fluxes. These observations are explained in terms of the effects of the laser beam's radiation pressure on the otherwise freely expanding plasma. The radiation pressure for a typical 10-J Q-switched ruby laser pulse with a half width of 65 nsec is equivalent to a maximum of 10 atm of pressure when focused to a 1-mm-diam spot.
LATTICE LOCATION OF DOPANT ELEMENTS IMPLANTED INTO Ge
Authors: Björkqvist K. , Domeij B. , Eriksson L. , Fladda G. , Fontell A. , Mayer J. W.
Published: January 2004

The orientation dependence of the backscattered yield of 1.8-MeV carbon ions has been used to determine the lattice location of In, Tl, Sb, Bi, and Pb ions implanted into Ge at 30–40 keV and at temperatures between 300° and 350°C. Similar to the behavior in silicon, the group IV and V elements are found to be highly substitutional. Thallium exhibits nearly equal numbers of atoms in the 〈111〉 interstitial sites and on the substitutional sites (as in Si). In indium implants, on the other hand, we find no evidence of the clearly defined interstitial component previously seen in Si. In all cases, we observe substitutional concentrations orders of magnitude above thermal equilibrium solubilities.
X-RAY DIFFRACTION TOPOGRAPHY WITH A VIDICON TELEVISION IMAGE SYSTEM
Authors: Chikawa Jun-ichi , Fujimoto Isao
Published: January 2004

Reproduction of x-ray diffraction topographic images has been made at about 25 diameters enlargement by a closed-circuit television camera system with an x-ray sensing Vidicon tube which utilizes a beryllium window and PbO photoconductive target. The height of video signals is exactly proportional to x-ray intensity, and intensity distribution can be observed as a video waveform. It is shown that the television image system can be used for rapid observations of topographic images such as Pendellösung fringes and imperfections in crystals, although its resolution (about 30 μ) is inferior to that of the photographic method.
A Nb TM010 MODE CAVITY WITH HIGH ELECTRIC FIELD AND Q0
Authors: Weissman Ira , Turneaure J. P.
Published: January 2004

A superconducting Nb TM010 mode cavity at 8.5 GHz machined from a single piece of reactor-grade electron-beam-melted Nb to avoid joints had an unloaded Q (Q0) of 2 × 1010. After some degradation in the Q0, which took place as the microwave fields were increased, a high Q0 of 1 × 109 was obtained at a peak electric field on the cavity surface of 27 MV/m. These results were obtained by using ultrahigh-vacuum firing and chemical polishing of the Nb cavity, and ultrahigh vacuum within the cavity during measurement. The high Q0 at high electric field demonstrates the usefulness of superconducting Nb cavities for devices such as linear particle accelerators and rf separators.
PHOTOSENSITIVE BARIUM TITANATE SCHOTTKY DIODES
Authors: Sawyer David E.
Published: January 2004

The observation of photocurrents generated in Schottky barrier diodes on Remeika-grown reduced barium titanate is reported. Photon-to-electron conversion efficiencies of 5% at 0.3 μm have been measured which suggests that the effect may be large enough for employment in practical devices.
RESPONSE OF THERMALLY SOFTENED DEFECT STRUCTURES IN ALLOYS TO AN APPLIED STRESS
Authors: Erdmann J. C. , Jahoda J. A.
Published: January 2004

Alloy specimens, after predeformation at 4.2°K and intermittent holding at higher temperatures, respond to reapplication of stress by transient evolution of heat. These heat bursts have been measured and are interpreted as due to the breakdown of unstable defect configurations.
EFFICIENT CW SECOND HARMONIC GENERATION TO 2573 Å
Authors: Dowley M. W.
Published: January 2004

Efficient cw second harmonic conversion to 2573 Å has been achieved in an argon laser cavity by means of the nonlinear materials ADP and KDP. Peak SH power was 415 mW which represented 50% efficiency. Trace impurities in the crystals prevented the realization of theoretical efficiency. An increase in cavity loss was observed during the simultaneous presence of fundamental and SH beams.
SOME SPECTRAL PROPERTIES OF DOUBLY AND SINGLY RESONANT PULSED OPTICAL PARAMETRIC OSCILLATORS
Authors: Bjorkholm J. E.
Published: January 2004

Spectral characteristics of doubly and singly resonant-pulsed optical parametric oscillators are experimentally compared. It is demonstrated that the tuning accuracy of the singly resonant oscillator is at least five times better than that of the doubly resonant oscillator. In addition, a singly resonant oscillator having an efficiency as good as that of a doubly resonant oscillator is described.
VACUUM ULTRAVIOLET PERTURBATION SPECTROSCOPY ON THE ARGON ION LASER
Authors: Merkelo H. , Wright R. H. , Kaplafka J. P. , Bialecke E. P.
Published: January 2004

Vacuum ultraviolet instrumentation compatible with simultaneous operation of the argon ion laser is described and perturbation spectroscopy on the resonance transitions of the argon ion is reported. Observations suggest a largely nonradiative destruction of the lower levels of the lasering transitions at current densities up to 300 A cm−2 and within a pressure range of 0.1 to 0.5 Torr.
PROBING OF GUNN EFFECT DOMAINS WITH A SCANNING ELECTRON MICROSCOPE
Authors: Robinson G. Y. , White R. M. , MacDonald N. C.
Published: January 2004

The high-field domains in a Gunn effect diode operating in the transit-time mode have been probed with a pulsed electron beam in a scanning electron microscope. The collected secondary emission current, when plotted as a function of both time and distance, clearly shows the propagation from cathode to anode of a region of high electric field. The probing technique is shown to offer micron spatial and subnanosecond temporal resolution.
HIGH POWER CO–N2–He LASER
Authors: Osgood R. M. , Eppers W. C.
Published: January 2004

High-power, high-efficiency lasing has been obtained from a flowing CO–Air–He laser. Maximum power was 20 W at 9% efficiency. The gas mixture was excited premixed in a liquid–N2–cooled discharge tube 144 cm long by 2 cm in diameter. Observations pertinent to the roles of the various gases are presented.
A NEW SURFACE WAVE IN PIEZOELECTRIC MATERIALS
Authors: Bleustein Jeffrey L.
Published: January 2004

A type of surface wave with no counterpart in a purely elastic homogeneous material is shown to exist in a piezoelectric material. Expressions for the velocity of propagation of this wave are obtained for various electrical boundary conditions on the free surface of a piezoelectric half-space.
CRYSTALLOGRAPHIC SYMMETRY OF SURFACE STATE DENSITY IN THERMALLY OXIDIZED SILICON
Authors: Arnold Emil , Ladell Joshua , Abowitz Gerald
Published: January 2004

The detailed dependence of surface state density on crystallographic orientation was determined by measuring the ac metal-oxide-semiconductor conductance on the surface of a thermally oxidized single-crystal silicon hemisphere. It was found that the 〈111〉 poles are located at maxima, the 〈100〉 poles at minima, and the 〈110〉 poles at saddle points in the surface state density distribution. The symmetry of the surface state density distribution is generally similar to that of the ``fixed'' interface charge density, but differences are noted in the vicinity of the 〈100〉 directions.
OXYGEN ISOTOPIC CONCENTRATION GRADIENT DETERMINATION WITH THE CAMECA ION MASS ANALYZER
Authors: Contamin P. , Slodzian G.
Published: January 2004

The ionic mass analyzer, built by Castaing and Slodzian, has been used for the determination of oxygen isotopic diffusion concentration gradients in massive uranium dioxide samples. Two methods have been investigated: image formation from surface isotopic distributions and ionic current measurements along the axis of diffusion.
PICOSECOND PULSE MEASUREMENT BY TWO-PHOTON EXCITATION OF PHOTOGRAPHIC FILM
Authors: Burnham David C. , Billman Kenneth W.
Published: January 2004

A simple technique for observing picosecond light pulses is demonstrated. The overlap between two light beams is measured by two-photon excitation of a photographic film which is below threshold for one-photon excitation. The resolution of the method is variable and limited only by the bandwidth of the photographic film.
STRONG MODE COUPLING INDUCED IN A GAS LASER BY AN INTRACAVITY SATURABLE ABSORBING MEDIUM
Authors: Feld M. S. , Javan A. , Lee P. H.
Published: January 2004

Although gas lasers generally operate in the weak mode-coupling regime, one may induce strong coupling, hence single-moding, by means of a saturable absorbing medium placed within the resonator. The effect occurs under conditions where, although the linear gain of the amplifier cell may exceed the linear loss of the absorption cell, the absorber may saturate more heavily than the amplifier. The analysis, based on the coupled energy-balance equations, indicates that the power in the surviving mode may be considerably enhanced.
NEAR-BAND-EDGE LUMINESCENCE IN GaAs:Zn
Authors: Arnold George W. , Brice David K.
Published: January 2004

The lasing transition in bulk Zn-doped GaAs has been resolved into three components (A′, B′, C′) with energies at 1.504, 1.489, and 1.484 eV, respectively. The higher energy levels are depopulated at low temperatures. The temperature dependence of the intensity of the transitions indicates a single luminescent center with a ground state and three excited states. A group-theoretical analysis based on the Td symmetry of the Zn acceptor with s1/2 conduction band electrons and p3/2 valence band holes leads to the conclusion that the luminescent center must have lower symmetry than Td. The various possible types of centers are mentioned but there are no a priori reasons for choosing one over the other at the present time.
EFFICIENT OPTICAL PARAMETRIC OSCILLATION USING DOUBLY AND SINGLY RESONANT CAVITIES
Authors: Bjorkholm J. E.
Published: January 2004

Efficient room-temperature optical parametric oscillation was obtained using a single-mode, giant-pulse ruby laser to directly pump a crystal of LiNbO3 placed in an optical cavity resonant at both the signal and idler wavelengths and also in a cavity resonant at only the signal wavelength. For the doubly resonant oscillator, 22% of the pump power was converted into signal power; for the singly resonant oscillator, conversion was 6%. The behavior of both oscillators was reproducible. Several features of the oscillator dynamics are discussed.
RESONANT AND ROUND-TRIP GAIN FOR ACOUSTOELECTRIC DOMAINS IN n-InSb
Authors: Dolat V. , Ross J. B. , Bray R.
Published: January 2004

Resonant and round-trip acoustoelectric gain are attainable in the high-mobility, piezoelectric semiconductor n-InSb, upon application of transverse magnetic fields. These features are demonstrated in the context of acoustoelectric domain formation and acoustoelectric instabilities. The elucidation of the basic features is greatly simplified by the use of constant-current pulses, which eliminate oscillatory effects.
STABILITY OF THE FLUX-FLOW STATE IN SUPERCONDUCTING NbTi STRIPS
Authors: Kroeger D. M. , Lubell M. S.
Published: January 2004

Experiments concerning termination of the flux-flow state have been performed on bare NbTi strips. For these strips of low heat capacity, take-offs occurred at powers less than the maximum heat flux in nucleate boiling. We conclude that take-off resulted from the simultaneous occurrence of a normal zone (caused by a local heat transfer fluctuation) and a current equal to or greater than the minimum propagating current.
OBSERVATIONS OF {111} ATOMIC PLANES IN SILICON
Authors: Phillips V. A. , Hugo J. A.
Published: January 2004

Using a Philips EM300 electron microscope and chemically thinned slices cut from a single crystal of silicon, the {111} atomic planes of 3.138-Å spacing have been imaged. A two-beam tilted illumination technique was employed.
FREQUENCY SHIFTS DURING GROWTH OF AMPLIFIED ACOUSTIC FLUX IN CdS
Authors: Balberg I. , Many A.
Published: January 2004

A simple experimental procedure based on measurements of the acoustoelectric after-current is described for estimating the frequency of maximum intensity of the amplified acoustic flux at various stages of its buildup. In CdS, the rapid buildup in flux leading to current saturation is followed by a slower growth which continues until the flux domain leaves the filament. The frequency of maximum intensity coincides initially with the frequency of maximum gain and decreases continuously as the domain propagates down the filament, reaching in a typical case a value ten times smaller.
C AXIS FLIPPING FOR MULTILAYER PIEZOELECTRIC THIN-FILM TRANSDUCERS
Authors: de Klerk J.
Published: January 2004

A method is described for flipping the direction of the c axes of consecutive active CdS or ZnS layers in multilayer piezoelectric transducers. Such transducers are capable of higher powers, broader bandwidths, and greater conversion efficiencies than either single-layer films or alternating active/passive multilayer films.
AN EXPERIMENTAL TEST OF PROPOSED WATER-VAPOR LASER TRANSITION ASSIGNMENTS
Authors: Jeffers W. Q.
Published: January 2004

The use of a double resonator with two single-wavelength paths has allowed experimental study of interactions among lines of a pulsed water-vapor laser. Twelve recent assignments of laser lines to transitions involving the (001), (100), and (020) states of H2O are confirmed. Ambiguity in the assignment of the line at 47.25 μ has been successfully resolved by this technique.
FAR-INFRARED PHOTOCONDUCTIVITY IN HIGH-PURITY EPITAXIAL GaAs
Authors: Stillman G. E. , Wolfe C. M. , Melngailis I. , Parker C. D. , Tannenwald P. E. , Dimmock J. O.
Published: January 2004

Extrinsic far-infrared photoconductivity has been observed at 4.2°K in high-purity n-type epitaxial layers of GaAs grown on Cr-doped semi-insulating GaAs substrates. Measurements of the responsivity and noise in the detection system at 300 Hz in a 1-Hz bandwidth yield an NEP of 1.2 × 10−11 W at 195 μ, 1.4 × 10−12 W at 337 μ and 6 × 10−11 W at 902 μ. The time constant of the detector has been determined to be shorter than 1 μsec using a Ge avalanche modulator to chop the incident radiation. A time constant of about 5 nsec has been measured using impact impurity ionization in the GaAs.
MODE FORMATION AND SELECTION IN A MODIFIED CONFOCAL RESONATOR
Authors: Beiser Leo
Published: January 2004

A resonator having a multiplicity of degenerate fundamental modes was formed of three mirrors in a split confocal arrangement with He–Ne as the laser active medium. It provided sufficiently low loss at 6328 Å to demonstrate mode selection by translation of an aperture near one end mirror. This configuration was adapted to sensitive measurement of mirror surface nonuniformity.
GUEST-HOST INTERACTIONS IN NEMATIC LIQUID CRYSTALS. A NEW ELECTRO-OPTIC EFFECT
Authors: Heilmeier G. H. , Zanoni L. A.
Published: January 2004

A new electro-optic effect is presented, based on guest-host interactions in nematic liquid crystals. The ability of a nematic liquid crystal to cooperatively align in an electric field is used to orient ``guest'' dichroic dye molecules (molecules whose absorption spectrum is a function of the molecular orientation with respect to the polarization of the incident light). Thus one can electrically switch the color of transmitted light using fields of the order of 104 V/cm.
SHEAR WAVE GENERATION AT MICROWAVE FREQUENCIES UTILIZING EPITAXIAL YIG FILMS ON YAG
Authors: Collins J. H. , Rubino N. , Zapp H. R. , Mee J. E. , Pizzarello F. A. , Pulliam G. R. , Hamilton T. N.
Published: January 2004

This Letter reports the generation of shear waves at microwave frequencies by magnetically biased epitaxial films of yttrium iron garnet deposited on yttrium aluminum garnet. These acoustic transducers are electronically tunable and permit single echos to be electronically selected from delayed pulse trains.
A CONFOCAL LONGITUDINAL MODE SELECTOR FOR SINGLE-FREQUENCY OPERATION OF GAS LASERS
Authors: Sinclair Douglas C.
Published: January 2004

A new type of mode selector is described which uses a short confocal cavity illuminated off-axis. The mode selector is generally similar to a Fox-Smith interferometer, but is easier to use, because it does not need to be mode-matched to the laser. Experimental results obtained using the confocal interferometer with an argon-ion laser are described.
A NONLINEAR TRAVELING-WAVE INTERACTION TECHNIQUE FOR MEASURING HOMOGENEOUS LINEWIDTHS
Authors: Shank C. V. , Schwarz S. E.
Published: January 2004

A new technique for measurement of collision-broadened homogeneous linewidths, using the nonlinear interaction between two traveling waves, is described. Measurements of homogeneous linewidth for the 6328-Å neon line in neon and helium-neon discharges are presented.
EVIDENCE OF LASER-INDUCED STIMULATED BRILLOUIN SCATTERING IN CdS
Authors: Kramer D. A. , Honig R. E.
Published: January 2004

Experimental results are presented which indicate two forms of damage in CdS irradiated by either a normalmode or Q-switched ruby laser at power densities near 108 W/cm2. The primary damage occurs as a deep crater coaxial with the incident laser beam. This crater contains many periodic transverse fractures whose spacing suggests a phonon frequency of ∼ 100 MHz, and which is attributed to stimulated Brillouin scattering. The second site is in the region where the refracted light beam exits from the crystal.
THE LASER TRANSITION AND PHOTON ENERGY OF GaAs IN THE LIGHTLY-DOPED LIMIT
Authors: Rossi J. A. , Holonyak N. , Dapkus P. D. , Williams F. V. , Burd J. W.
Published: January 2004

Data are presented showing that lightly doped or relatively pure GaAs lases basically by a band-to-band recombination transition at a photon energy at threshold of 1.495 eV ≈ Eg − 0.015 eV (∼77°K). The ∼0.015-eV energy reduction from bandgap, which is greater than the exciton binding energy of 0.0034 eV (∼77°K) and unlike the exciton energy is dependent upon carrier concentration, occurs because of many-body, electron-hole-lattice (EHL) interactions.
FREQUENCY- AND TIME-DEPENDENT GAIN CHARACTERISTICS OF LASER- AND FLASHLAMP-PUMPED DYE SOLUTION LASERS
Authors: Bass M. , Deutsch T. F. , Weber M. J.
Published: January 2004

Dye solution lasers are observed to lase at shorter wavelengths when laser pumped than when flashlamp excited. A comparison of the computed frequency- and time-dependent gains for the two pumping methods explains this behavior and the observed Q dependence of the lasing frequency. This treatment also suggests a new technique for frequency tuning dye lasers.