bluuebunny/crossref_metadata_2025 huggingface dataset:
MOS STUDY OF INTERFACE-STATE TIME CONSTANT DISPERSION
Authors: Nicollian E. H. , Goetzberger A.
Published: March 2005

The time constant dispersion of states at the Si–SiO2 interface measured by the MOS conductance technique in the depletion region is too broad to be explained by the continuum model alone. By assuming that built-in charges and charged interface states are randomly distributed over the plane of the interface, the resulting fluctuations of surface potential lead to a time constant dispersion which agrees with experiment. An explanation is also given of the single time constant observed at each bias in weak inversion for the continuum of states.
A PHYSICAL MODEL OF THE ELECTRO-OPTIC EFFECT
Authors: Kurtz S. K. , Robinson F. N. H.
Published: March 2005

A physical model of the electro-optic effect is presented which is based on an extension of Bloembergen's anharmonic oscillator model for nonlinear optical processes. Expressions for the electro-optic coefficients of centrosymmetric and noncentrosymmetric crystals are derived and shown to be in good agreement with experiment. Miller's empirical relation between the linear and nonlinear susceptibilities is also explained for the electro-optic case.
PROPERTIES OF 1/2 〈110〉, {111} GLIDE DISLOCATIONS IN ELASTICALLY ANISOTROPIC FCC METALS
Authors: Duncan T. R. , Kuhlmann-Wilsdorf D.
Published: March 2005

The shear stresses and elastic energies associated with edge dislocations of 1/2 〈110〉, {111} type in cubic anisotropy are discussed.
MEASUREMENT OF SOME MOLECULAR VIBRATIONAL-ROTATIONAL PARAMETERS WITH AN INFRARED HETERODYNING TECHNIQUE
Authors: Kovacs M. A. , Rhodes C. K. , Szöke A. , Javan A.
Published: March 2005

Frequency mixing of three simultaneously oscillating P-branch laser transitions can be used to obtain accurate spectroscopic information on some of the molecular rotational-vibrational parameters. This has been demonstrated for the 10-μ laser transitions of CO2 and N2O. The present accuracy is limited by the Doppler widths of the infrared molecular transitions. Improved accuracy is possible to within a small fraction of the Doppler width. Furthermore, it is shown that at elevated pressures where pressure broadening is comparable to or exceeds the Doppler width, mode coupling occurs and the laser tends to oscillate on a single axial mode.
INFRARED ABSORPTION IN HIGH-PURITY BORON FILMS
Authors: Zimmerman William , Murphy Anne M. , Feldman Charles
Published: March 2005

The infrared spectra of high-purity amorphous boron films showed no absorption peaks in the 2–15-μ region. It is shown that the major peaks previously reported may be attributed to oxide, hydroxide, or carbon contamination.
SLOW-ELECTRON BEAM ATTENUATION BY GOLD FILMS
Authors: Kanter H.
Published: March 2005

An attenuation length of 34 Å for electrons with 6-eV energy above the Fermi level was found by penetration of slow-energy electron beams through gold films about 200-Å thick. The collector current was determined for various primary energies as a function of film thickness, which was increased in situ by vapor deposition. The attenuation length, representative of electron-electron collisions, decreased to 29 Å, for an increase of energy of 1 eV.
DAMPING OF SUSTAINED CURRENT OSCILLATIONS IN SEMICONDUCTING CADMIUM SULPHIDE AT HIGH FIELDS
Authors: Stanley I. W.
Published: March 2005

Sustained current oscillations in semiconducting cadmium sulphide which are strongly damped at high electric fields have been observed. It is suggested that they arise from cyclic changes in the spatial distribution of acoustic flux generated by acoustic-electric interaction.
THREE-BEAM HOLOGRAPHY
Authors: De Manoranjan , Sévigny Léandre
Published: March 2005

A new method of holographic interferometry is proposed, which makes use of three-beam interference for the production of the hologram. A single exposure is then sufficient to produce the hologram from which the interferogram may be reconstructed in the usual manner. In one form, the reconstructed interferogram has double the sensitivity to phase variation as compared to conventional single-pass and double-exposure holographic interferometry. In another form, one may reconstruct the usual interferogram and also the original object wave simultaneously.
TIME-RESOLVED MEASUREMENTS OF STIMULATED BRILLOUIN SCATTERING
Authors: Maier M. , Rother W. , Kaiser W.
Published: March 2005

In CS2 a quasistationary state is observed with Brillouin power increasing linearly with laser power. High conversion efficiency up to 90% is found within a few millimeters of the liquid cell. In toluene intense Brillouin pulses occur with power values exceeding the instantaneous laser power.
OBSERVATION OF TRANSIENT FLUX MOTION IN Sn FILMS
Authors: Stewart W. C. , Cosentino L. S.
Published: March 2005

Cumulative flux transport across a tin film carrying direct current is observed in pulsed magnetic fields of alternating polarity by direct detection of the generated emf and by buildup of trapped flux in a coupled superconducting loop.
ELECTRICAL RESISTIVITY CHANGES IN THIN METALLIC FILMS DUE TO ION IRRADIATION
Authors: Navinsek B. , Carter G.
Published: March 2005

The change in electrical resistance of thin Ag, Au, Ti, and W films was studied following energetic A+ ion bombardment. There is an initial reduction in film resistance (for all materials) during bombardment, which is attributed to removal of surface contaminant gas. The resistance then increases to a quasiequilibrium value, which is believed to be due to introduction of radiation damage to the films, and finally the resistance increases rapidly as the films sputter and thin.
CONTINUOUS-WAVE SUBMILLIMETER OSCILLATION IN DISCHARGES CONTAINING C, N, AND H OR D
Authors: Müller Walter M. , Flesher Gail T.
Published: March 2005

Experimental observations are presented of the continuous oscillation of a submillimeter laser using gaseous compounds of C, N, and H or D, the relative independence of the output on the particular gases used, and the effect of the addition of water or He. With pure (CN)2 no laser action was obtained, but addition of H2O or D2O gave two different sets of laser lines. At present, in the region between 107.71 and 336.83 μ, ten laser lines have been obtained with dc excitation.
FREQUENCY STABILIZATION OF THE ZEEMAN LASER
Authors: Kannelaud J. , Peterson D. G. , Culshaw W.
Published: March 2005

The intensity crossover region with cavity tuning between oscillations on two orthogonally circularly polarized axial modes of a Zeeman laser has been used to stabilize these oscillation frequencies with respect to the center of the atomic transition. In contrast to previously proposed stabilization schemes this method allows operation over a wide range of frequencies off the center of the atomic transition, providing step and vernier tuning. The stabilization method has been successfully applied to the 0.633-μ and 1.153-μ He–Ne and 2.65-μ Xe lasers. A frequency stability of one part in 1010 was obtained with the 2.65-μ Xe laser.
LOW-ENERGY ELECTRON DIFFRACTION STUDIES OF EPITAXIAL GROWTH OF SILVER AND GOLD IN ULTRAHIGH VACUUM
Authors: Palmberg P. W. , Rhodin T. N. , Todd C. J.
Published: March 2005

The occurrence of epitaxial growth of single-crystal films of silver and gold has been found to depend critically on exposure of the substrate surface to an electron beam prior to deposition. Single-crystal films with a (100)∥(100), (100)∥(100) orientation were produced on irradiation surfaces at low supersaturation levels in the absence of contaminating gases. It is proposed that the controlled production of point defects on the clean surface play a critical role in the nucleation and growth required for epitaxy.
A NEW CLASS OF LOW-PRESSURE ARC COLUMNS WITH POSITIVE V-I CHARACTERISTICS
Authors: Meyer H. J. G. , Ahsmann G. , van der Laarse J. W.
Published: March 2005

This Letter reports a new class of arc columns in the torr-pressure range which in a wide range of voltages are voltage-determined. The arc columns consist of mixtures of some noble gas seeded with tiny amounts of alkali vapor (pressure about 3 × 10−4 torr). At a certain critical current a very strong rise, by a factor of 4 or more, in column gradient occurs, accompanied by very striking visual changes in the column. An explanation in terms of the concept of ``donor depletion'' is given, the ``donor'' atoms being the alkali atoms. Possibilities for practical applications are mentioned.
ENHANCEMENT IN A Ho3+–Yb3+ QUANTUM COUNTER BY ENERGY TRANSFER
Authors: Esterowitz L. , Noonan J. , Bahler J.
Published: March 2005

In all the infrared quantum counter systems reported to date, a single rare-earth ion dopant was used as the activator. This limits the optimum concentration to about 1%, since above this value nonradiative processes begin to dominate. In order to increase the number of ions which can absorb the infrared signal Yb3+ was used as a sensitizer. By making use of the energy transfer from Yb3+ to Ho3+ the green quantum counter fluorescence was increased by more than two orders of magnitude.
HIGH-FIELD HALL EFFECT OF SEMICONDUCTING CdS
Authors: Miyake Tohru , Onuki Masami
Published: March 2005

Hall voltage and conductivity of semiconducting CdS crystals with different mobilities have been measured at high pulsed electric fields. The electron density is nearly constant in a wide range of field which includes the field of current saturation. At fields above 2.1 × 103 V/cm, electron multiplication due to impact ionization is observed. In the case of an electric field parallel to the c axis of the crystal, the Hall drift velocity at the saturation field is determined by the interaction of electrons with off-axis shear waves of sound.
MEASUREMENT OF PHOTON ABSORPTION LOSS IN THE ACTIVE AND PASSIVE REGIONS OF A SEMICONDUCTOR LASER
Authors: Hunsperger R. , Ballantyne J.
Published: March 2005

A technique is described for measuring the photon absorption coefficients in the active and passive regions of an electron-beam-pumped semiconductor laser. Measurements made at 4°K on n-type, single-crystal GaAs indicate that photon loss in the active region is due to free carrier absorption, and that this absorption coefficient increases linearly from 2.5 cm−1 to 47 cm−1 as donor concentration is varied from 2.4 × 1017 cm−3 to 4.7 × 1018 cm−3. For each case the active region absorption coefficient is less than that measured in the passive region, which varies from 354 cm−1 to 98 cm−1 over the same range of donor concentrations. The increased loss in the passive region is attributed to interband absorption transitions.
LOW-ENERGY ELECTRON DIFFRACTION OBSERVATIONS OF α-ALUMINA
Authors: Charig J. M.
Published: March 2005

Low-energy electron diffraction observations of a single crystal of α-alumina have revealed a reversible structural transformation on the (001) surface. The transformation is a function of the temperature of heat treatment of the alumina.
FILM PLANE HOLOGRAMS WITHOUT EXTERNAL SOURCE REFERENCE BEAMS
Authors: Rosen Lowell , Clark William
Published: March 2005

Reasonable quality holograms have been made of objects placed within 1 to 3 cm of the hologram plane without the need for any external reference beam. The reconstructions from such holograms, though not of high quality, are clearly recognizable and three-dimensional.
MULTIPLE QUANTUM RESONANCE SPECTROSCOPY THROUGH WEAKLY CONNECTED SUPERCONDUCTORS
Authors: Silver A. H. , Zimmerman J. E.
Published: March 2005

Voltage-biased superconducting weak contacts have been used as oscillating detectors to observe radio-frequency absorption spectra including the Co59 nuclear magnetic resonance in ferromagnetic cobalt. The detection is attributed to multiple quantum processes and differentiation of the dynamic I-V characteristics. Used as a spectrometer, the point contact is shown to be a continusously tunable ultra-low power oscillator-detector from 0 to 3 × 108 Hz. It is likely that the frequency limit could be extended to the superconducting gap frequency.
ABSOLUTE FREQUENCY MEASUREMENT AND SPECTROSCOPY OF GAS LASER TRANSITIONS IN THE FAR INFRARED
Authors: Hocker L. O. , Javan A. , Rao D. Ramachandra , Frenkel L. , Sullivan T.
Published: March 2005

Absolute frequencies of the 311-μ and the 337-μ transitions of the CN gas laser are measured to within a few parts in 107. This is achieved by mixing the laser frequencies with high order harmonics of a microwave signal in a silicon diode. The beat frequencies of these two transitions which falls at 73.5 GHz is also measured directly. The Zeeman effect of these two laser transitions is studied. Based on a detailed analysis, it is found that the existing identification of these transitions is inconsistent with our observations.
ULTRASONIC IMAGING USING A SYNTHETIC HOLOGRAPHIC TECHNIQUE
Authors: Preston K. , Kreuzer J. L.
Published: March 2005

Visible three-dimensional ultrasonic imaging of the interior and exterior of optically opaque objects has been achieved using a synthetic holographic technique at a frequency of 5 MHz. One ultrasonic hologram and the corresponding visible image are presented.
OPTICAL HETERODYNE MEASUREMENT OF NEON LASER'S MILLIMETER WAVE DIFFERENCE FREQUENCY
Authors: Hall J. L. , Morey W. W.
Published: March 2005

We report detection and measurement of the millimeter wave difference frequency between two near laser lines at 1.152 μ. The two spectral transitions, separated by 2.26 Å, oscillate in pure neon in a single laser device, producing about 150 μW total power in several longitudinal modes. The many resulting 51.3-kmc beat frequencies have been studied by optical heterodyne techniques. A type of diode has been found which has enough microwave sensitivity and enough optical sensitivity to combine the optical detector and the microwave heterodyne functions in a single element. The preliminary value for the difference in frequency between the and 2S4 → 2P7 transitions in neon at 150 mtorr is (51,360 ± 150) Mc. This value is not in agreement with the value calculated from Vol. I of Sitterly's Atomic Energy Levels (ref. 12).
PHOTOCONDUCTIVITY IN p-TYPE SINGLE-CRYSTAL PbS FILMS
Authors: Davis John L. , Riedl H. R. , Schoolar R. B.
Published: March 2005

Photoconductivity has been observed in p-type single-crystal films of PbS. The results suggest that the photoconductive mechanism in these films is the same as that in the highly sensitive p-type polycrystalline PbS detectors.
COMPLEX STIMULATED RAMAN VIBRATIONAL-ROTATIONAL SPECTRA IN HYDROGEN
Authors: Johnson F. M. , Duardo J. A. , Clark G. L.
Published: March 2005

Highly complex stimulated Raman scattering (SRS) spectra of hydrogen were produced by using narrow linewidth 1.058-μ giant-pulsed laser excitation. Results are presented which include the first reported observation of combination Raman lines whose frequencies are given by mvQ(1) + pvS(1) − vL where vQ(1), vS(1) and vL are the vibrational (4155 cm−1), rotational (587 cm−1) and laser frequency, respectively, m = 6, 7, or 9 and p = 0 or ±1. Numerous Raman lines described by the formula v = vL + mvQ(1) + nvS(0) + pvS(1), (m, n, p = 0, ±1, ±2,…), where vS(1) = 354 cm−1, were also observed.
LASER ACTION FROM TERBIUM TRIFLUOROACETYLACETONATE IN p-DIOXANE AND ACETONITRILE AT ROOM TEMPERATURE
Authors: Bjorklund Sven , Kellermeyer G. , Hurt C. R. , McAvoy N. , Filipescu N.
Published: March 2005

Laser activity has been obtained from terbium tris (1, 1, 1-trifluoroacetylacetonate) at room temperature in a liquid solution in acetonitrile and in p-dioxane. Threshold pumping energy is about 1700 J. Characteristic line narrowing, spiking and beam collimation was exhibited.
DIELECTRIC AND ELECTRO-OPTIC PROPERTIES OF LEAD MAGNESIUM NIOBATE
Authors: Bonner W. A. , Dearborn E. F. , Geusic J. E. , Marcos H. M. , Van Uitert L. G.
Published: March 2005

Low-frequency dielectric constant measurements vs temperature and electric field indicate that the ferroelectric transition in Pb3MgNb2O9 is second order. The quadratic electro-optic coefficients in Pb3MgNb2O9 are approximately an order of magnitude smaller than those of KTN (KTa.65Nb.35O3); however, the electronic conduction effects and compositional inhomogeneity problems encountered in KTN are absent in Pb3MgNb2O9, thus making it a practically useful electro-optic material.
ELASTIC SURFACE WAVES IN QUARTZ AT 316 MHz
Authors: Arzt R. M. , Salzmann E. , Dransfeld K.
Published: March 2005

Elastic surface waves in quartz have been excited at 316 MHz by a method which seems also to be promising for even higher frequencies up to a few GHz. The temperature dependence of the absorption in quartz has been studied between 2°K and 300°K. When the quartz is immersed in liquid helium, an additional attenuation due to radiation on longitudinal waves into the fluid occurs which turns out to be noticeably higher than estimated.
THERMAL SWITCHING OF LASER EMISSION OF Er3+ AT 2.69 μ AND Tm3+ AT 1.86 μ IN MIXED CRYSTALS OF CaF2:ErF3:TmF3
Authors: Robinson M. , Devor D. P.
Published: March 2005

Pronounced temperature-dependent transfer of excitation from the Er3+ laser pump levels to lower levels of Er3+ was observed in CaF2:ErF3 single crystals at ErF3 concentrations exceeding 12.5 wt %. Transfer of excitation from Er3+ to Tm3+ occurred when TmF3 was included as a second active constituent of the crystals. Stimulated emission of the 4I11/2 → 4I13/2 transition of Er3+ at 2.69 μ at 298°K resulted independently of Tm3+ and as a consequence of concentration quenching of emission of Er3+ from levels above 4I11/2. At 100°K reduced transfer of excitation to 4I11/2 of Er3+ occurred due to radiative emission from levels above 4I11/2, and laser emission of Tm3+ was detected at 1.86 μ.
A STUDY OF STRESS WAVES PRODUCED BY PULSED HIGH-ENERGY RADIATION
Authors: Peffley W. M.
Published: March 2005

Transient pulses of 10-MeV electrons from a linear accelerator were employed to generate stress waves in cylindrical rods of various materials. A piezoelectric accelerometer was used to determine the velocity of the induced stress wave and monitor the acceleration experienced by the end of the bar. A solution of the one-dimensional wave equation, as altered by a specific thermoelastic term which acts as a forcing function exciting a finite bar, was obtained. The resulting qualitative agreement with the experimental findings is discussed.
PRESSURE DEPENDENCE OF DISLOCATION MOBILITY IN ALKALI HALIDE CRYSTALS
Authors: Davis L. A. , Gordon R. B.
Published: March 2005

By means of differential pressure compression tests the pressure dependence of the plastic flow stress of NaCl, KCl, and LiF is measured. The measured flow stress change can be related directly to the change in dislocation mobility. In NaCl and KCl, screw dislocation mobility is decreased under pressure by more than the shear modulus is raised; the effect is nearly zero in LiF.
ENHANCED STAGE I RECOVERY OF DEFORMED ALUMINUM
Authors: Swanson M. L. , Quenneville A. F.
Published: March 2005

The stage I recovery of deformed Al amounts to approximately 4.5%, independent of the degree of deformation, but is increased by a factor of four by a large prior deformation and low temperature anneal. The recovery curves are almost linear from 20–50°K, indicating that the activation energy distribution of the defects responsible for this recovery is rather uniform. A likely explanation of the enhanced recovery is that the defects which are rearranged in stage I become disarrayed again by subsequent deformation.
CENTRAL TUNING DIP IN A SUBMILLIMETER MOLECULAR LASER
Authors: Pollack M. A. , Bridges T. J. , Strnad A. R.
Published: March 2005

A central tuning dip (or ``Lamb dip'') has been observed in the power output of a CW molecular laser operating at 118.6 μ. The collision broadened linewidth was calculated from the shape of the dip. From the dependence of the linewidth on pressure, a radiative lifetime of 0.64 μsec and a pressure broadening (full width) of 10 MHz/torr H2O can be estimated. Comparisons with published results for OH and H2O do not yield sufficient information to identify either as the lasing species.
UPPER-CRITICAL-FIELD LIMITS FOR BULK TYPE-II SUPERCONDUCTORS
Authors: Hake R. R.
Published: March 2005

Approximate zero-temperature upper-critical-field limits Hc20 (max), consistent with the recent extreme-type-II theory of Werthamer, Helfand, and Hohenberg (WHH), are deduced by assuming (1) an electron mean free path l0 comparable to the interatomic spacing, (2) a spin-orbit-coupling-induced spin-flip mean free path lso=2l0, with approximate applicability of the WHH theory in this domain, and (3) Tc and l-independent parameters typical of present-day high-field superconductors. Highest Hc20(max) ≈ 850 kG are obtained for high-Tc β-tungsten-structure compounds.
DIFFRACTION OF LIGHT BY ELASTIC WAVES IN YIG
Authors: Dixon R. W. , Matthews H.
Published: March 2005

The first observations of light diffracted by elastic waves propagating in a ferrimagnetic material (yttrium iron garnet) are reported and discussed, and the values of the photoelastic tensor components of YIG are presented.
PARAMETRIC COUPLING BETWEEN ION WAVES AND ELECTROMAGNETIC WAVES
Authors: Sjölund A. , Stenflo L.
Published: March 2005

Parametric coupling between longitudinal ion waves and transverse electromagnetic waves in a plasma is studied. The possibilities of exciting ion waves and electron waves by means of this coupling mechanism are considered, and the growth rates are compared.
MAGNETIC AND OPTICAL PROPERTIES OF TRANSPARENT RbNiF3
Authors: Shafer M. W. , McGuire T. R. , Argyle B. E. , Fan G. J.
Published: March 2005

Magnetic and optical data on single-crystal RbNiF3 are presented. We conclude that this material is ferrimagnetic, rather than antiferromagnetic as previously reported, with a transition temperature of 139°K and a saturation moment of 21 emu/g at 4.2°K. The basal plane is the preferred plane and the out-of-plane anisotropy is 106 ergs/cc. The Faraday rotation measured along the c axis at 77°K and 80% of magnetic saturation exhibits a peak value of 400° per cm at a wavelength of 4950 Å and values of 250° to 50° per cm in the region 5000 to 6000 Å where the optical absorption is lowest.
P-N JUNCTIONS IN GaP WITH EXTERNAL ELECTROLUMINESCENCE EFFICIENCY ∼2% AT 25°C
Authors: Logan R. A. , White H. G. , Trumbore F. A.
Published: March 2005

The external electroluminescent quantum efficiency at 25°C of GaP p-n junctions grown by liquid-phase epitaxy on solution-grown substrates may be increased by as much as an order of magnitude by annealing, after growth, at temperatures in the range 400°C–725°C for times ∼16 hr. Typical efficiencies obtained range from 1–2%. The I-V characteristic consists of two parallel components: a small tunneling current and a recombination current in the space charge region. The effect of annealing is to increase the efficiency in proportion to the decrease in current, at a given bias.
SPIN-WAVE INTERACTION WITH A LASER BEAM IN YIG
Authors: Wang S. , Thomas G.
Published: March 2005

Experimental results are presented concerning the interaction of a Nd laser beam with spin waves in YIG in the subsidiary absorption region. The microwave power was held below the threshold for spin-wave instability. When hit by a laser beam, the sample showed characteristic magnetoelastic and relaxation oscillations. The same oscillations were observed without the laser beam if the microwave power was raised above the threshold for spin-wave instability. The result provides evidence of spin-wave excitation in YIG by a laser beam.
ELECTRONIC TUNING OF NARROW-BAND DETECTORS
Authors: Medved D. B. , Rolik G. P.
Published: March 2005

Photodiode detectors having narrow spectral response without use of external filters have been fabricated. Use of high resistivity semi-insulating GaAs in the construction of such diodes makes it possible to modulate the spectral response by application of moderate values of reverse bias. A device is described whose spectral response is expanded from a half-width of ∼ 200 Å to typical broad-band characteristics under 30 V reverse bias.
ORIENTATION EFFECTS OF AN APPLIED DC FIELD ON NaCl FILMS DEPOSITED ON SILICA GLASS
Authors: Sinclair W. Robert , Calbick Chester J.
Published: March 2005

Reflection electron diffraction patterns show strong variations in orientations of the outer layer of an NaCl film deposited on fused silica, due to the presence during evaporation of a dc field parallel to the surface.

Orientation effects have been observed by x-ray diffractometry in a limited range of evaporation rates which are attributed to electrolysis of adsorbed water.
TIME EVOLUTION OF PICOSECOND OPTICAL PULSES
Authors: Glenn W. H. , Brienza M. J.
Published: March 2005

A high-speed energy correlation technique has been used to measure the time development of the width of the ultrashort pulses generated by a mode-locked Nd+3 glass laser. The laser was simultaneously Q-switched and mode-locked with a saturable absorber and produced a train of approximately 100 ultrashort pulses. It was found that the initial pulses in the train were of the shortest duration and that the pulse width increased from several picoseconds to about 15 picoseconds over the length of the train. The measurement technique and possible mechanisms for this behavior are discussed.
GENERATION OF COMBINATION TONES BY THE INTERACTION OF ORTHOGONAL OSCILLATIONS IN A GAS LASER
Authors: Doyle W. M. , White M. B.
Published: March 2005

A theoretical expression is given for the amplitudes of the combination-tones which result from the interaction of orthogonal laser oscillations. Combination-tone generation is found to be highly dependent upon the degree of degeneracy of the atomic energy levels involved and upon the polarization states of the primary oscillations. The theoretical predictions are compared with the results of an experimental study of combination-tone phenomena in He-Ne lasers.
VISIBLE SIDE-LIGHT EMISSION PROPERTIES OF A CO2–N2–He PLASMA INDUCED BY THE CO2 LASER RADIATION FIELD
Authors: Crane R. Anthony , Waksberg Armand L.
Published: March 2005

The effect of laser action, in CO2 laser plasmas, on the spontaneous emission in the visible spectral region is studied by means of a phase-lock technique. The results reveal that direct collisions between molecules in the primary laser cycle and highly excited states have an important influence on the properties of the plasma.
NONLINEAR EFFECTS IN IMAGE FORMATION
Authors: Gerritsen Hendrik J.
Published: March 2005

The use of nonlinear effects in image processing is discussed, particularly in connection with holography. A new type of microscope, called a holoscope, is described which permits true three-dimensional magnification.
FIELD-ENHANCED PHOTOEMISSION FROM LARGE-AREA Ge DIODES AT LOW TEMPERATURES
Authors: Davies I. G. , Thornton P. R.
Published: March 2005

Experimental observations on FEPE from large-area Ge diodes at low temperatures (∼90°K) are reported. These data include values of the device quantum efficiency as a function of wavelength and bias. An effect is reported in which photon-induced changes in emissive current are observed at wavelengths up to 2 μ, i.e. well beyond the absorption edge, with efficiencies 4 × 10−5. Aging characteristics associated with this long wavelength effect are described. A tentative suggestion is made that the effect is due to photon-induced changes in the surface field leading to changes in field emission.
OBSERVATION OF MISFIT DISLOCATIONS IN GaAs–Ge HETEROJUNCTIONS
Authors: Krause G. O. , Teague E. C.
Published: March 2005

Epitaxial heterojunctions have been prepared by chemical vapor deposition of Ge onto (001) GaAs substrates using the hydrogen reduction of GeCl4. Scanning x-ray microscopy revealed a cross-grid of dislocation lines at the interface. It is believed that these two sets of misfit dislocations in the interface plane result from a partial accommodation of the lattice mismatch between Ge and GaAs.
THE GROWTH OF SINGLE-CRYSTAL FILMS OF CUBIC SILICON CARBIDE ON SILICON
Authors: Khan I. H. , Summergrad R. N.
Published: March 2005

Thin single-crystal films of cubic silicon carbide have been grown on silicon substrates within the temperature range 800- 1000°C in high and ultrahigh vacuum by the reaction of unsaturated hydrocarbons, C2H and C2H4 with silicon. The cubic silicon carbide grows with a parallel orientation onto silicon, regardless of crystal orientation. The use of ultrahigh vacuum results in high crystal perfection.
SOME OBSERVATIONS ON THE ELECTROMIGRATION IN ALUMINUM FILMS
Authors: Ghate P. B.
Published: March 2005

Thin-film aluminum resistors with thermally grown SiO2 as the substrate have been subjected to very high current densities of the order 0.5 to 2 × 106 A/cm2. The temperature of the resistor is estimated to be (185 ± 15)°C at high current densities. It is observed that an opening occurs in most of these resistors close to the cathode. Experimental evidence is presented to show that electromigration leads to the observed failures in these thin-film aluminum resistors.
ELECTRO-OPTIC COEFFICIENTS OF FERROELECTRIC STRONTIUM BARIUM NIOBATE
Authors: Lenzo P. V. , Spencer E. G. , Ballman A. A.
Published: March 2005

Linear electro-optic coefficients as large as r ∼ 4 × 10-5 cm/statvolt have been measured in the system of ferroelectric strontium barium niobates, SrxBa1-xNb2O6. In the first crystals x varies from 0.75 to 0.25, with Curie temperatures ranging from ∼60°C to 250°C. At 15 Mc, the respective half-wave field distance products range from 48 to 1236 V.
MAGNETOELASTIC WAVES IN PULSED MAGNETIC FIELDS
Authors: Rezende S. M. , Morgenthaler F. R.
Published: March 2005

An analysis of magnetoelastic waves propagating in spatially uniform, time varying magnetic fields is carried out using small signal momentum conservation. The equations of motion are cast in coupled mode form and the usual weak coupling (between positive and negative waves) approximation is made. The magnon/phonon conversion efficiency for propagation in time gradients is then obtained by analogy to the result previously found for the case of spatial gradients. Experiments which support the theory are described briefly.
INFRARED ABSORPTION DUE TO FREE ELECTRONS IN CdSe
Authors: Hase N. , Onuki M.
Published: March 2005

The infrared absorption coefficient due to free electrons in a melt-grown CdSe crystal is measured as a function of the wavelength at 300 and 80°K. Using densities of free electrons and ionized impurities obtained by measurements of Hall effect and conductivity, experimental results on the infrared absorption are compared with the Visvanathan theory which is applicable to the absorption due to electrons in a polar semiconductor.
DIFFRACTION OF LIGHT BY MAGNETOELASTIC WAVES
Authors: Smith Archibald W.
Published: March 2005

Diffraction of light at 1.15 μ has been observed from magnetoelastic waves at 1.1 GHz in YIG. A shift in the Bragg diffraction angle was observed when an external magnetic field was varied so as to change the spin wave admixture. The largest shift obtained experimentally was -2.0°, measured from the elastic limit of 9.5°. This shift was accompanied by a delay in the diffracted pulse of about 1 μsec. Under quasielastic conditions the diffracted intensity exhibited a series of maxima as the field was swept, due to magnetoelastic Faraday rotation.
DESORPTION OF SURFACE ATOMS BY EMERGING HIGH ENERGY ELECTRONS
Authors: Pollard J. H. , Danforth W. E.
Published: March 2005

High energy electrons penetrating a solid and emerging from a surface can remove surface atoms by Coulomb interaction with their nuclei. Observations of this desorption process were made on a (100) tungsten surface with an adsorbed layer of thorium atoms of known coverage. Electrons of energy up to 2 MeV were used and the rate of removal of thorium atoms was calculated from the rate of change of work function of a collector surface. Measurements of desorption rate as a function of energy suggest a binding energy of 15 to 20 eV, in contrast to the 8 eV obtained from thermal desorption.
NONMECHANICAL TORQUE-DRIVEN FLOW OF A FERROMAGNETIC FLUID BY AN ELECTROMAGNETIC FIELD
Authors: Moskowitz R. , Rosensweig R. E.
Published: March 2005

Flows of ferromagnetic fluids (colloidal suspensions) are obtained by coupling to the suspended single-domain particles with a rotating magnetic field. It is shown that very high rotation rates are possible by this technique. Nonmechanical torque-driven flows represent a hitherto unexplored area in the physics of fluids that has interesting potential technological application. A ferromagnetic pump based upon the present principle could be of great value in fluidic systems and open up new applications in space, ocean, biological and other environments.
PHASE-MATCHED FOUR-FREQUENCY INTERACTIONS IN CALCITE
Authors: Kavage W. T.
Published: March 2005

Two phase-matched four-frequency mixing experiments in calcite are reported: ω0 (6943 Å) + ω1 (8727 Å) = ω2 (1.175 μ) + ω3 (5764 Å) and 2ω0 (6943 Å) = ω2 (8727 Å) + ω3 (5764 Å) where for index matching, θ = 7.40° and 5.25°, respectively.
SOUND WAVE INTERACTIONS IN InSb
Authors: Kino G. S. , Route R.
Published: March 2005

In high-mobility piezoelectric semiconductors such as InSb, a transverse magnetic field greatly reduces the electron drift velocity required to form an acoustoelectric domain. We have developed a theory which predicts this effect reasonably well. We have also shown that when these materials are used as acoustic amplifiers, the magnetic field reduces the dc power dissipation at maximum acoustic gain to such a large degree that CW amplification of sound waves can easily be achieved.
DOUBLE INJECTION AND HIGH FREQUENCY NOISE IN GERMANIUM DIODES
Authors: Driedonks F. , Zijlstra R. J. J. , Alkemade C. Th. J.
Published: March 2005

Negative resistance and oscillations were observed in germanium diodes, operating in forward direction. Conductance and noise measurements were done in the post-negative resistance region, where the current voltage characteristic obeys the cube law for a plasma injected into an insulator. The conductance g shows a transit time effect, and the h.f. noise can be represented by a noise current generator (4kTgΔf)1/2 in parallel to the device.
HIGH SPEED MEASUREMENT OF TWO-PHOTON ABSORPTION PROCESSES
Authors: Panizza E.
Published: March 2005

A new technique useful to set a lower limit for the lifetime of the intermediate state of two-photon absorption processes is described. The technique is applied to the case of two-photon absorption in CdS.
MÖSSBAUER SPECTRA BY MEANS OF A VARIABLE-FREQUENCY ULTRASONIC SPECTROMETER
Authors: Bolef D. I. , Mishory J.
Published: March 2005

The construction and method of operation of a variable-frequency ultrasonic Mössbauer spectrometer is described. Application is made to the well-known hyperfine spectrum of Fe57 in a natural iron foil absorber.
HIGH-POWER MICROWAVE NONLINEAR COUPLING TO ACOUSTIC RESONANCES IN A WARM PLASMA
Authors: Asmussen Jes , Beyer James B.
Published: March 2005

The nonlinear high-power coupling of microwave power to electroacoustic resonances which are at a harmonic of the driving frequency, ω1, is discussed. Experimental results that indicate the existence of this nonlinear coupling are presented, and a one-dimensional theory which includes the thermal properties of the plasma is briefly developed. The inclusion of the temperature phenomena allows one to explain previously unexplained resonances in harmonic output.
FRONT-LIGHTED PULSE LASER HOLOGRAPHY
Authors: Siebert L. D.
Published: March 2005

Photographs of holograms made with a single-mode pulsed ruby laser are shown. Holograms were made of a variety of front-lighted motion scenes including a fan rotor, jet spray, hand pouring milk from a beaker, and a smoke stream.
METHOD FOR PRODUCTION OF BLAZED OPTICAL DIFFRACTION GRATINGS FROM SINGLE-CRYSTAL MATERIALS
Authors: Blakely J. M.
Published: March 2005

A new technique for fabricating optical diffraction gratings of specified blaze angle is described. The method is based on the formation of a periodic, thermodynamically stable, faceted surface. This arises from variation in surface free energy with surface orientation.
HIGH-OUTPUT POWERS AND LONG LIFETIMES OF SEALED-OFF CO2 LASERS
Authors: Witteman W. J.
Published: March 2005

Output powers up to 63 W/m and lifetimes in excess of 1000 hr are obtained with sealed-off CO2 lasers. The addition of 0.2 torr H2O or 0.2 torr H2 to the convential mixture of CO2, N2, and He is essential for obtaining these results. The influence of the observed OH radials on the extended lifetime is discussed.
SEARCH FOR RESONANCE BEHAVIOR IN THE MICROWAVE DIELECTRIC CONSTANT OF GaAs
Authors: Champlin K. S. , Erlandson R. J. , Glover G. H. , Hauge P. S. , Lu T.
Published: March 2005

In a recent communication, Larrabee and Hicinbothem presented measurements of the dielectric constant of high-resistivity GaAs showing a region of anomalous dispersion centered at 9.5 GHz. We have made similar measurements over the frequency range between 8.5 and 70 GHz but have not obtained their results. Our measurements indicate that the relative dielectric constant is independent of frequency in the microwave range and equal to 12.95 ± .10 at room temperature.
THE DIELECTRIC CONSTANT OF GaAs AT MICROWAVE AND MILLIMETER WAVE FREQUENCIES
Authors: Jones Stan , Mao Shing
Published: March 2005

The dielectric constant of Cr-doped semi-insulating GaAs has been measured from 4 to 40 GHz. Contradictory to the anomalous variation in this range reported by R. D. Larabee and W. A. Hicinbothem, Jr., for oxygen-doped S-I GaAs, no frequency dispersion was observed.
DIELECTRIC CONSTANT AND LOSS TANGENT OF SEMI-INSULATING GaAs AT MICROWAVE FREQUENCIES
Authors: Rogers C. B. , Thompson G. H. B. , Antell G. R.
Published: March 2005

The dielectric constant of gallium arsenide has been measured over the frequency range around 9.5 GHz where a resonance has been reported. No evidence of an appreciable variation in dielectric constant was observed. An accurate measurement at 9.4 GHz gave a dielectric constant of 12.35 and a loss tangent of 5.6 × 10−4.
AN EPR STUDY OF THE EFFECT OF SUBSTRATE ORIENTATION ON VAPOR-GROWN GaP
Authors: Taylor R. C. , Title R. S.
Published: March 2005

The results of EPR and resistivity measurements on vapor-grown GaP are discussed. The study shows that the appearance of Fe3+ EPR signals and the resistivity values are dependent on substrate orientation. A model based on the formation of Ga vacancies during growth is proposed to account for the observations.
IMAGING AND STORAGE WITH A UNIFORM MOS STRUCTURE
Authors: Phelan R. J. , Dimmock J. O.
Published: March 2005

Radiation sensitive characteristics of a uniform InSb—metal-oxide-semiconductor (MOS) structure have been used to detect images. By rapid optical scanning this structure with visible light of 0.63 μ we have detected infrared images due to 5-μ radiation. In addition information can be read-in and stored (or ``photographed'') by using 1-μ radiation, nondestructively read-out with 5-μ radiation, and erased with 0.25-μ radiation.
EPITAXIAL GROWTH OF GOLD AND SILVER ON MAGNESIUM OXIDE CLEAVED IN ULTRAHIGH VACUUM
Authors: Palmberg P. W. , Rhodin T. N. , Todd C. J.
Published: March 2005

Single-crystal, high-purity films of silver and gold were formed by ultrahigh vacuum deposition on surfaces of magnesium oxide cleaved in vacuum. Epitaxial characteristics were studied in situ at various stages of formation by LEED and on stripped films by electron microscopy and high energy electron diffraction. It is significant that well-ordered epitaxial (100) Au and (100) Ag films were obtained on untreated MgO surfaces cleaved in UHV. Nucleation at -195°C or severe electron bombardment followed by deposition at 200°C produced gold films with (111) fiber-axis orientations.
RELAXATION OF THE 10.6 μ CO2 LASER LEVELS BY COLLISIONS WITH H2
Authors: Cheo P. K.
Published: March 2005

Time characteristics of the afterglow gain of a pulsed CO2:H2 laser amplifier were investigated. Evidence shows that a rapid nonradiative transfer of population from the upper to the lower CO2 laser levels occurs at higher H2 pressures (P ≥ 2 torr). An absorption pulse on the order of 1 msec in duration following the initial gain period is attributed to population accumulation (or a bottleneck) at the 0101 level.
FREQUENCY SPECTRUM OF ACOUSTIC WAVES GENERATED IN PHOTOCONDUCTING CdS IN HIGH ELECTRIC FIELDS
Authors: Zemon S. , Wasko J. H. , Hope L. L. , Zucker J.
Published: March 2005

Using Brillouin scattering of a 6328 Å He–Ne laser beam, we have investigated the properties of acoustic shear waves generated in high-resistivity, photoconducting CdS in high electric fields. The data were analyzed using modifications to the Bragg law valid for birefringent materials. The frequency of maximum acoustic intensity varied as the square-root of carrier concentration from 150 MHz to 375 MHz.
MULTIPLE STIMULATED BRILLOUIN SCATTERING FROM A LIQUID WITHIN A LASER CAVITY
Authors: Alcock A. J. , De Michelis C.
Published: March 2005

By inserting a liquid cell between the ruby and the output reflector of a high power, passively Q-switched ruby laser, marked changes in pulse shape, output power and spectral characteristics were observed. These effects are explained in terms of stimulated Brillouin scattering, from the liquid, effectively replacing reflection from the output mirror above a well-defined power level. Time-resolved Fabry-Perot interferograms confirm this explanation and reveal that the output actually consists of a number of pulses, overlapping in time and corresponding to successive Brillouin orders.
LASER-INDUCED MICROWAVE SOUND BY SURFACE HEATING
Authors: Brienza M. J. , DeMaria A. J.
Published: March 2005

Microwave sound of discrete frequencies has been generated by the irradiation of a solid with the uniformly spaced, ultrashort optical pulses produced by a mode-locked Nd:glass laser. The sound, rich in harmonic content, has its fundamental frequency fixed by the repetition frequency of the laser pulses. Believed to be thermally generated in the optical skin depth where the energy is absorbed, the sound has been detected at room temperature up to 2 GHz, the tenth harmonic of the fundamental repetition frequency. Such high harmonic content indicates that the acoustic pulses have rise times significantly less than 1 nsec and demonstrates the feasibility of utilizing ultrashort laser pulses to produce ultrashort acoustic pulses.
QUASI-CW, HIGH NUMERICAL APERTURE, INDUCTIVELY EXCITED ION LASER
Authors: Zarowin C. B. , Williams C. K.
Published: March 2005

Taking advantage of the wide bandwidth possible with inductive excitation at audio-frequencies, square-wave excitation at 2.5 kHz has been employed to obtain laser oscillation of the 4880-Å ArII transition in a high numerical aperture active medium 1 cm in diam and 15 cm long, without the aid of an axial magnetic field.
OBSERVATION OF PHASE OBJECTS BY OPTICALLY PROCESSED HILBERT TRANSFORM
Authors: Lowenthal Serge , Belvaux Yves
Published: March 2005

A method for observing phase objects, based on the Hilbert transform is defined. This is achieved by spatial filtering.

The amplitude images obtained are characterized by their high luminosity. The objects are correctly imaged, even if the phase varies slowly (low frequency objects), which is not the case with conventional methods such as the phase contrast and central dark ground methods.

The method also permits easy measurement of geometrical aberrations, for the Hilbert transforms of aberrant wavefronts are more easily interpreted than with the Foucault method.
OPTICAL SUM GENERATION OF THE TWO-FREQUENCY OUTPUT OF A GIANT PULSE RUBY LASER
Authors: Bradley Daniel J. , Magyar George , Richardson Martin C.
Published: March 2005

The tunable, two-frequency output of a gain-switched ruby laser, has been mixed in ADP to generate the sum frequency. A conversion efficiency for sum frequency generation equal to that of SHG has been consistently achieved.
A NEW PHOSPHOR FOR FLYING-SPOT CATHODE-RAY TUBES FOR COLOR TELEVISION: YELLOW-EMITTING Y3Al5O12–Ce3+
Authors: Blasse G. , Bril A.
Published: March 2005

The fluorescence of Y3Al5O12–Ce3+ under cathode-ray excitation consists of an emission band peaking at 550 nm. The decay time is 0.07–0.08 μsec. In view of these properties this phosphor is very suitable for flying-spot cathoderay tubes for color television.
HIGH TEMPERATURE RESONANCE LOSSES IN SILICON-DOPED YTTRIUM—IRON GARNET (YIG)
Authors: Epstein D. J. , Tocci L.
Published: March 2005

The ferrimagnetic resonance linewidth of silicon-doped YIG, measured as a function of temperature at 13.4 kMHz, is found to show a pronounced peak at 105°C. The anisotropic behavior of this peak is in good agreement with the four-level valence-exchange model proposed by Clogston. The model yields for the electron ordering energy a value 5 × 10-4 eV which agrees closely with the energy deduced from magnetic anneal studies. The activation energy for electron transfer (0.25 eV) is virtually identical with values reported in investigations of electrical conductivity and acoustic loss.
THE FORMATION OF THE MACROVORTEX STRUCTURE IN HARD SUPERCONDUCTORS
Authors: Iwasa Y. , Williams J. E. C.
Published: March 2005

Measurements of the field at the surface of a magnetized hard superconducting wire have shown that the application of a local perturbation precipitates the sequential formation of a spatially periodic magnetization (macrovortex structure) along the axis of the wire.
ON THE EXPLANATION OF THE SO-CALLED CN LASER
Authors: Lide David R. , Maki Arthur G.
Published: March 2005

It is shown that the major features of the far-infrared ``CN laser'' are due to the HCN molecule. The intense line at 337 μ and other nearby lines are explained as transitions involving the 1110 and 0400 vibrational states, which are mixed by a Coriolis perturbation. The mechanism of the laser is discussed.
PHOTOGRAPHIC STUDIES OF LASER-INDUCED PRESSURE IMPULSES IN LIQUIDS
Authors: Carome E. F. , Carreira E. M. , Prochaska C. J.
Published: March 2005

Shadow photography techniques have been used to study various effects produced in transparent liquids by the focused beam from a Q-spoiled ruby laser. The intense spherical acoustic transients generated in water and other pure liquids when dielectric breakdown occurs have been examined. In solutions of benzanthracene in benzene, in which other workers have detected two-photon absorption, a linear region is strongly affected by the laser beam and cylindrical acoustic disturbances have been observed.
NUCLEATION OF CRYSTALS IN MULTILAYER METALLIC ADSORBATES
Authors: Gretz R. D. , Pound G. M.
Published: March 2005

The adpopulations of zinc, cadmium, nickel, and gold which are critical for appreciable nucleation rate of crystallites on clean tungsten field emitter tips have been measured. These critical adconcentrations range from 1.1 monolayers for cadmium to 3.7 monolayers for nickel and are independent of temperature from 75°K to above room temperature. This phenomenon can be described by none of the existing theories of heterogeneous nucleation.
THERMOELASTIC STRESS PULSES RESULTING FROM PULSED ELECTRON BEAMS
Authors: Graham R. A. , Hutchison R. E.
Published: March 2005

Measurements of the elastic stress pulses induced by the absorption of intense 2-MeV electron pulses in disks of quartz, sapphire, silicon, and an aluminum alloy are reported. The relative stress amplitudes and pulse durations agree with those predicted from the thermoelastic characteristics of the absorbers and the properties of the electron pulse.
OPTICAL PATTERNS OF THERMALLY SELF-DEFOCUSED LIGHT
Authors: Callen W. R. , Huth B. G. , Pantell R. H.
Published: March 2005

In this Letter we discuss the observation of a pattern of concentric annuli formed as a result of thermal effects upon a light beam. To our knowledge, this is the first time such patterns have been reported.

When a beam of light passes through an absorbing medium whose refractive index decreases as a function of temperature, the medium behaves as a negative lens. Gordon et al.1 observed this phenomenon by placing a cell containing an absorbing liquid between the mirrors of a helium-neon laser. The absorption constants for several liquids with very low absorbencies have been determined using this effect.2 Rieckhoff3 measured the increase in the diameter of a light beam that passed through a thermal self-defocusing liquid placed external to the laser inter-ferometer. Recently Leite et al.4 demonstrated that this effect may be used as a power limiting device.