bluuebunny/crossref_metadata_2025 huggingface dataset:
DEPENDENCE OF SECOND-HARMONIC PHASE-MATCHING TEMPERATURE IN LiNbO3 CRYSTALS ON MELT COMPOSITION
Authors: Fay Homer , Alford W. J. , Dess H. M.
Published: January 2004

The second-harmonic, phase-matching temperature of ``stoichiometric'' LiNbO3 crystals, for fundamental radiation at 1.06 μ, has been found to vary by as much as 75°C from crystal to crystal and 10°C within an individual crystal. Measurements on crystals grown in a controlled manner from nonstoichiometric melts have shown that the phase-matching temperature, T, is an approximately linear function of melt composition, x, obeying the equation T = 50.5 + 32 × 102 (x − 0.50). Crystals with phase-matching temperatures of as high as 186°C have been grown from melts containing excess lithia. Such a crystal has been operated as a second harmonic generator without damage, whereas a comparable radiation produced by a crystal with a low phase-matching temperature damaged the crystal. A mechanism involving lithium ion vacancies is proposed to explain the results.
COHERENCE PROPERTIES OF THE SUPERRADIANT 5401 Å PULSED NEON LASER
Authors: Leonard Donald A. , Zinky William R.
Published: January 2004

The spatial and temporal coherence of the 5401 Å pulsed neon laser were measured experimentally. These measurements show that although the laser operates in a purely superradiant mode with zero feedback amplification, the output can be coherent over the entire duration of a 2 nsec pulse.
DEPENDENCE OF RADIATIVE EFFICIENCY IN GaP DIODES ON HEAT TREATMENT
Authors: Onton A. , Lorenz M. R.
Published: January 2004

Room temperature electroluminescence peaks at 1.80 and at 1.37 eV in GaP diodes doped with Zn and O are shown to be related. Emission can be shifted from one peak to the other by heat treatments. It is proposed that those emission peaks correspond to recombination at nearest neighbor Zn–O pairs and pairs at larger separations, respectively. The thermal activation energy associated with the transformation of red emission centers to infrared emission centers is 0.54 ± 0.15 eV.
PASSIVE Q SWITCHING OF THE CO2 LASER BY VINYL CHLORIDE
Authors: Yardley James. T.
Published: January 2004

One P-branch line, tentatively identified as P18 or P20, of the 00°1 → 10°0 transition of CO2 has been passively Q switched, using vinyl chloride as the saturable absorber. Average power is roughly the same as that obtained using pure SF6 for Q switching. The observed pulse width is about 2 μsec and the time between pulses is about 20 μsec.
THERMAL EFFECTS AND TRANSVERSE MODE CONTROL IN A Nd:YAG LASER
Authors: Osterink L. M. , Foster J. D.
Published: January 2004

By compensating for the thermal lens effect in a Nd:YAG rod, we have substantially increased the fundamental transverse mode CW power available from the laser. To date, we have obtained over 1.4 W in the TEM00 mode, compared to about 200–300 mW without compensation. The ratio of TEM00 mode power to multimode power is dependent on the pump power, and appears to be related to thermal lens aberrations which occur through the photoelastic effect in the rod. The results of an analysis of the thermal focusing effect in YAG are also included.
TIME-RESOLVED STIMULATED EMISSION SPECTRA OF AN ORGANIC DYE LASER
Authors: Farmer G. I. , Huth B. G. , Taylor L. M. , Kagan M. R.
Published: January 2004

The output from a transverse-pumped organic dye laser has been investigated using time-resolved spectroscopy. It is found that for the specific case of DTTC-Iodide dissolved in either DMSO or methanol the peak wavelength in the emission band shifts during the output pulse.
PIEZO- AND THERMO-OPTIC BEHAVIOR OF LiNBO3
Authors: Vedam K. , Davis T. A.
Published: January 2004

The variation of the ordinary and the extraordinary refractive indices of LiNbO3 with hydrostatic pressure to 7 kbar has been measured by an interferometric method. Both the indices for λ 5893 Å were found to increase linearly with pressure with slopes of 0.32 × 10−3/kbar and 0.69 × 10−3/kbar respectively for the ordinary and extraordinary rays. An analysis of these results and the published data on the variation of the refractive indices of LiNbO3 with temperature, reveal that the pure temperature effect on polarizability is very large in this material.
THE ABSORPTION COEFFICIENT OF GaAs AT MICROWAVE AND MILLIMETER WAVE FREQUENCIES
Authors: Bichara Marcel R. E.
Published: January 2004

Measurements of the absorption coefficient of GaAs have been made on low resistivity (0.176 Ω-cm, n-type) and high resistivity (> 106 Ω-cm, p-type) samples for frequencies between 1.8 and 100 GHz. In both cases the theoretical values expected, derived using classical electromagnetic theory, were confirmed by those obtained experimentally, thus throwing doubt on the existence of the unexplained variation of the dielectric constant with respect to frequency found by Larrabee and Hicinbothem.
THE CRITICAL THICKNESS AND COERCIVITY OF Co-Ni-Fe FILMS
Authors: Gorres J. M. , Hanson M. M.
Published: January 2004

The critical thickness for stripe domain formation and the coercivity dependence on thickness of vapor-deposited Co–Ni–Fe films have been found to depend strongly on the cobalt melt percentage. The critical thickness was found to increase and the coercivity dependence on thickness to decrease as the melt cobalt content is increased.
SUBNANOSECOND SCHLIEREN PHOTOGRAPHY OF LASER-INDUCED GAS BREAKDOWN
Authors: Alcock A. J. , DeMichelis C. , Hamal K.
Published: January 2004

Second harmonic radiation from a mode-locked neodymium:glass laser, providing a 400-nsec-long train of picosecond pulses, has been used as a light source for Schlieren photography of a laser-induced spark. The beam from a ruby laser, Q-switched by means of a Pockels cell, was focused in air to produce breakdown and synchronization of the two lasers was achieved by switching the Pockels cell with a spark gap illuminated by the mode-locked pulse train.
MANY-BODY WAVELENGTH SHIFT IN A SEMICONDUCTOR LASER
Authors: Holonyak N. , Johnson M. R. , Rossi J. A. , Groves W. O.
Published: January 2004

Under conditions of negligible heating, optical excitation of thin, homogeneous semiconductor platelets to higher levels increases the number of longer wavelength laser modes without loss of the shorter wavelength modes. This relative shift to longer wavelength operation as a function of excitation is attributed to many-body interactions.
THE EPITAXY OF COPPER ON SAPPHIRE
Authors: Katz Gerald
Published: January 2004

Epitaxial twinned single-crystal films of copper have been grown on sapphire substrates by high vacuum evaporation in the temperature range 240–-375°C. The presence of a twin relationship in copper deposited on the basal plane of sapphire was demonstrated and evaluated by x-ray diffraction techniques. The epitaxy has been shown to be (111)Cu ∥ (0001)α−Al2O3; [21̄1̄)Cu ∥ [21̄1̄0]α−Al2O3. The films have been found to exhibit the bulk metal resistivity.
BANDWIDTH REDUCTION OF HOLOGRAM TRANSMISSION SYSTEMS BY ELIMINATION OF VERTICAL PARALLAX
Authors: De Bitetto D. J.
Published: January 2004

A technique is described which reduces the bandwidth required for holographic data transmission by eliminating vertical parallax. This is accomplished by transmitting only the information in a thin horizontal strip of a conventional hologram. The receiver is required to reproduce many identical copies of this strip hologram, and present them simultaneously in a vertical array for viewing. Horizontal parallax and a panoramic three-dimensional view are preserved. Experimental results of feasibility tests are described.
MODE-LOCKED PULSE GENERATION IN PASSIVELY SWITCHED LASERS
Authors: Fleck J. A.
Published: January 2004

The behavior of a passively switched laser is described by a set of partial differential equations, which are integrated numerically. For short upper-state lifetimes of the absorbing medium, the calculated output of the laser is a train of narrow pulses. Pulses occur either singly or in multiples during the roundtrip time 2L/c, depending on whether the absorber is near one mirror or at an intermediate position.
A DEMONSTRATION OF LASER PUMPING USING A COMPRESSED GAS LIGHT SOURCE
Authors: Dowling James A. , Shumsky Jack , Eckerman Jerome , Schlier Robert E. , Kisatsky Paul
Published: January 2004

Xenon gas has been compressively heated to temperatures of from 8000 to 15,000°K in a ballistic compressor system. Brightness measurements of the light pulses produced indicate blackbody radiation at these temperatures. The radiation has been coupled into a neodymium-doped glass laser rod with resulting laser action. The system affords a direct transfer of mechanical energy into pumping radiation without the necessity of intermediate energy storage devices.
ALPHA-IODIC ACID: A SOLUTION-GROWN CRYSTAL FOR NONLINEAR OPTICAL STUDIES AND APPLICATIONS
Authors: Kurtz S. K. , Perry T. T. , Bergman J. G.
Published: January 2004

The linear and nonlinear optical properties of α-HIO3 have been measured in the visible and near-infrared. Phase-matched second harmonic generation is shown to occur for both parallel and orthogonal input polarizations. The observed phase-matching surfaces are in agreement with theory. In addition, (a) large single crystals of high optical quality are easily grown from water solution; (b) the measured nonlinear coefficient d14 is slightly larger than d31 in LiNbO3; and (c) no ``optical damage'' effects occur at high power densities. Preliminary results indicate that a substantial number of iodates exhibit similar nonlinear optical properties.
STUDY OF OPTICAL DIFFERENCE MIXING IN Ge AND Si USING A CO2 GAS LASER
Authors: Wynne J. J. , Boyd G. D.
Published: January 2004

Measurements are made of the nonlinear optical effect third order in electric field strength in Ge and Si using a CO2 laser operating at 10.6 μ and 9.2 μ. The effect is due to bound electrons and is described by a fourth-rank electric susceptibility tensor. The crystals show anisotropy in the nonlinear coefficients whose absolute values are consistent with Miller's phenomenological theory. Comparison is made with the measured values of calcite.
COHERENT FLUORESCENCE FROM ZINC SULFIDE EXCITED BY TWO-PHOTON ABSORPTION
Authors: Wang S. , Chang C. C.
Published: January 2004

Emission of coherent radiation was observed from ZnS which was excited through two-photon absorption of radiation from a giant-pulse ruby laser. The spectral width decreased from 75 to 12.8 Å above a threshold ruby-laser power of 35 MW/cm2. Photographic pictures showed a beam divergence of less than 1°.
MEASUREMENT OF X RAYS AS A FUNCTION OF MASS IN THE THERMAL FISSION OF U235
Authors: Bohn E. M. , Wehring B. W. , Wyman M. E.
Published: January 2004

Characteristic K x rays from thermal neutron fission of U235 were studied as a function of the fission fragment mass. With a NaI (Tl) detector viewing the first 1 cm of fragment paths, x rays in coincidence with fission were recorded together with the fragment energies as detected by silicon surface-barrier detectors. Results are reported for yields of K x rays as a function of fragment mass. The most probable charge for various masses is estimated.
FOCUSING OF A LASER BEAM BY AN ACTIVE CdS OSCILLATOR
Authors: Wang W. C. , Das P.
Published: January 2004

A strong lens effect has been experimentally observed when the electric field inside a CdS plate is so adjusted that strong quasi-standing ultrasonic waves are set up inside the crystal. Physical understanding of the observed phenomena and possible device applications are discussed.
THE EFFECT OF DISLOCATIONS ON THE VAPORIZATION RATE OF NaCl SINGLE CRYSTALS
Authors: Lester J. E. , Somorjai G. A.
Published: January 2004

The vacuum evaporation rates of the (100) face of sodium chloride single crystals were measured in the temperature range 770–900°K. By increasing the dislocation density in the NaCl crystals (106 to 107 cm−2) the steady-state vacuum evaporation rates were increased by a factor of two. The vapor composition remained unchanged over the different dislocation density crystals.
EFFECT OF HEATING UNDER BIAS ON PHOTOELECTRIC THRESHOLD IN MOS STRUCTURE
Authors: Viswanathan C. R. , Ogura Seiki
Published: January 2004

Experimental evidence of change in photoelectric threshold energy for emission of electrons from silicon into oxide in MOS structure, due to heating under biased conditions is given. A model to explain this behavior has been proposed.
PHOTOMULTIPLIER DETECTION OF 10.6 μm RADIATION USING OPTICAL UP-CONVERSION IN PROUSTITE
Authors: Warner J.
Published: January 2004

Synthetic single-crystal proustite pumped with collimated pulsed ruby laser radiation has been used to convert 10.6 μm radiation to the visible. Measured values of photon conversion efficiency (Ns/Nir = 1.4 × 10−6) and phase-matched bandwidth (540 Å at 10.6 μm) are in good agreement with theory.
STIMULATED EMISSION FROM FLASHLAMP-EXCITED ORGANIC DYES IN POLYMETHYL METHACRYLATE
Authors: Peterson O. G. , Snavely B. B.
Published: January 2004

Laser emission is reported from flashlamp-excited polymethyl methacrylate rods containing rhodamine dyes. Quenching of stimulated emission by the molecular triplet state is apparently reduced in the solid with respect to that observed for the same dyes in liquid solution.
TIME DEPENDENCE IN THE THERMAL BLOOMING OF LASER BEAMS
Authors: Carman R. L. , Kelley P. L.
Published: January 2004

The time dependence of the thermal defocusing of a laser beam has been studied. Under certain conditions the beam is found to expand linearly with time, under others it expands with a time dependence approaching t1/2.
COMMENTS ON CORRELATION BETWEEN ELECTROLUMINESCENCE AND ELECTRON EMISSION OF THIN METAL-OXIDE-METAL SANDWICHES
Authors: Kanter H.
Published: January 2004

It is shown experimentally that only at ``larger'' field strengths is the electron current from cold-cathode Al–Al2O3–Au structures dominated by photoelectron emission released in the top layer through electroluminescence radiation within the oxide.
THERMAL PRODUCTION OF A POPULATION INVERSION IN CARBON DIOXIDE
Authors: Wisniewski E. E. , Fein M. E. , Verdeyen J. T. , Cherrington B. E.
Published: January 2004

A population inversion for the 00°1 → 10°0 (10.6 μ) transition in CO2 has been created by resonant collisional transfer of excitation from thermally excited N2.
SUPERCONDUCTIVITY IN EVAPORATED TUNGSTEN FILMS
Authors: Basavaiah S. , Pollack S. R.
Published: January 2004

Tungsten films were found to be superconducting at 3.2°K. Upon investigation by x-ray and electron diffraction, a β-W (A15) structure was evident. Superconducting tunneling studies revealed that the ratio 2Δ(0)/kTc varied from 2.32 and 3.64 and Δ(T)/Δ(0) vs T/Tc followed the BCS theory.
PASSIVE MODE LOCKING OF A CO2 LASER
Authors: Wood O. R. , Schwarz S. E.
Published: January 2004

Self-locking of longitudinal cavity modes has been observed in a CO2–N2–He laser with an SF6 absorber inside the cavity. Pulses as short as 20 nsec, with peak power in the range 104–105W, have been obtained. Pulse trains longer than 100 μsec have been observed. Operation is repetitive at millisecond intervals.
THE DETECTION OF OIL OR MERCURY ON SURFACES IN VACUUM SYSTEMS USING AN ELLIPSOMETER
Authors: Fane R. W. , Neal W. E. J. , Rollason R. M.
Published: January 2004

The application of an ellipsometer to the detection of oil or mercury contamination of surfaces in vacuum systems is discussed. Tables giving instrument readings for these contaminants on appropriate substrates illustrate the feasibility of the technique.
ANOMALOUS DIFFUSION OF NICKEL IN SINGLE CRYSTALS OF LEAD SELENIDE AT 700°C
Authors: Swaroop B. , Wagner J. B.
Published: January 2004

The diffusion of nickel into undoped and silver-doped, p-type lead selenide crystals exhibits anomalous behavior at 700°C. The penetration profiles show pronounced minima and these minima migrate into the crystal as a function of time. The minima occur when there is a p to n transition in the initially p-type crystals. The diffusion of nickel into n-type, bismuth-doped crystals does not exhibit a minimum in the penetration profile of nickel and the crystals do not exhibit an n to p transition.
SLOW PULSES FROM A PLANAR Ge(Li) DETECTOR
Authors: Sakai Eiji
Published: January 2004

When a very good planar Ge(Li) detector (3.8 cm2 × 9 mm, ∼77°K, ∼1 kV/cm) was irradiated by a slit-collimated 137Cs γ-ray beam (slit width, ∼0.25 mm) incident parallel to the n+ -i and the i-p junctions, a large and abrupt increase in the relative counting rate of slow rising pulses was observed near the two junctions. The slow pulses had much longer rise times (> 0.5 μsec) than those of the normal fast rising pulses whose rise times were determined by the transit times of the carriers.
A SIMPLE ANALYSIS OF THE PROPAGATING ACOUSTOELECTRIC HIGH-FIELD DOMAIN
Authors: Mosekilde E.
Published: January 2004

An analytical treatment of the uniformly propagating acoustoelectric high-field domain is presented in the limit of zero diffusion. Expressions for the electron density and the acoustic energy density as functions of the electric field are given. The domain velocity is determined.
HOLOGRAPHIC INTERFEROMETRY WITH ULTRAVIOLET LIGHT
Authors: Wuerker R. F. , Heflinger L. O. , Briones R. A.
Published: January 2004

Simultaneous red and ultraviolet holographic interferograms were recorded on a single Eastman 649F plate by radiation existing after the passage of a Q-switched ruby laser beam through a KDP crystal. The ultraviolet record had twice the sensitivity to optical path length changes as the red record.
GROWING SURFACE WAVES IN A SEMICONDUCTOR IN THE PRESENCE OF A TRANSVERSE MAGNETIC FIELD
Authors: Kino G. S.
Published: January 2004

Recent observations of growing carrier waves in InSb suggest a new type of interaction involving electrons and holes which leads to a growing surface wave. A theory is presented which shows that the wave has a phase velocity near the electron drift velocity, and in the presence of a transverse magnetic field is unstable with very large growth rates.
MULTIJOULE PULSES FROM CO2 LASERS
Authors: Hill Alan E.
Published: January 2004

A high voltage transient pumping technique is reported whereby 5-J 200-kW CO2 laser pulses have been produced in a 3-in.-diam, 8-ft discharge tube. This device, operating at repetition rates of 35–100 pulses per second, produced 210 W maximum average power. Similar devices of 1-in. through 6-in. diameters indicate that, unlike continuous-wave CO2 lasers, this pulsed system may be extended at least to 6-in. diam and/or to total pressures in excess of 60 torr, without severe loss of plasma uniformity. Preliminary scaling experiments indicate that further increases in peak and average power might be achieved.
DETERMINATION OF SURFACE COMPOUND FORMATION BY BACKSCATTER MÖSSBAUER SPECTROSCOPY
Authors: Terrell J. H. , Spijkerman J. J.
Published: January 2004

The detection and identification of a surface compound formation on a steel surface was made using a backscatter Mössbauer effect technique. The compound was identified as β-FeOOH from Mössbauer effect parameters of iron oxide and oxy-hydroxide compounds. An estimate of the compound thickness is given based on a calculation of the backscatter amplitude versus distance into the sample. This technique can be used to identify corrosion products on the surface of iron bearing materials.
SECOND HARMONIC GENERATION IN LiNbO3 BY PICOSECOND PULSES
Authors: Shapiro S. L.
Published: January 2004

Short pulses emitted by a Nd:glass laser were passed through LiNbO3 crystals to produce SHG (second harmonic generation) of tunable duration. The duration of the SHG pulse was tuned between 1.5 psec and 9 psec by varying the length of the LiNbO3 crystals.
ACOUSTICAL HOLOGRAPHY OF NONEXISTENT WAVEFRONTS DETECTED AT A SINGLE POINT IN SPACE
Authors: Metherell A. F. , Spinak S.
Published: January 2004

An experiment is described in which a hologram is recorded by scanning the source and having the detector stationary. The resulting ``scanned source'' hologram is shown to be identical to the conventional ``scanned detector'' hologram. The significance of this experiment is that it demonstrates: (1) that sampled holograms of an object can be recorded at a single point in space with either a scanning source or an array of sources; (2) that the object wavefront need not actually exist in space but may be geometrically synthesized; (3) that the object may be illuminated by a changing rather than stationary wave field. The interesting possibilities which this configuration gives rise to are briefly discussed.
MAGNETIC PARAMETRIC NUCLEAR SPIN SATURATION
Authors: Tanttila W. H. , Mahler R. J. , James L. W.
Published: January 2004

Parametric magnetic Δm = ±2 nuclear spin transitions are observed when an rf magnetic field at the frequency (Em−2 − Em)/h is applied parallel to a large, externally applied, magnetic field in a ruby crystal where the symmetry axis of the cylindrically symmetric electric field gradient tensor (the c axis in ruby) is perpendicular to the external magnetic field.
ON THE IONIZATION STATE OF FIELD EVAPORATED ATOMS AS MEASURED IN THE FIM-ATOM PROBE
Authors: Brenner S. S. , McKinney J. T.
Published: January 2004

Experiments to test the performance of an FIM-atom probe have yielded data on the charge state of field-evaporated atoms from clean tungsten and iridium surfaces. These data are presented and discussed in the light of current ideas about the process of field evaporation.
NUCLEATION DENSITY AND EPITAXY OF GOLD DEPOSITED ONTO COLOR-CENTERED CLEAVAGE SURFACE OF ROCKSALT
Authors: Inuzuka Tadao , Ueda Ryuzo
Published: January 2004

The vacuum deposition of gold upon the color-centered surface of NaCl produced by x-ray irradiation is described. The increase of nucleation density and the enhancement of (100) parallel orientation are observed. It appeared that these findings in experimental results compared with the phenomena on the normal cleavage surface were attributable to the effects of point imperfections produced. A lowering of epitaxial temperature is also observed. The controlled production of imperfections on the surface by irradiation has a critical effect upon the nucleation and epitaxial growth.
DETERMINATION OF THE CRYSTALLOGRAPHIC POLARITY OF CdS BY ION SCATTERING
Authors: Strehlow W. H. , Smith David P.
Published: January 2004

The crystallographic polarity along the [0001] direction of wurtzite CdS single crystals was determined by ion scattering. The energy distributions of 2-keV He+ ions scattered from the polar surfaces of CdS show this method to be very sensitive for distinguishing between the (0001)Cd and (0001̄)S face.
RELATIVE SIGNS OF THE OPTICAL NONLINEAR COEFFICIENTS d31 AND d22 IN LiNbO3
Authors: Bjorkholm J. E.
Published: January 2004

It has been found that the optical nonlinear coefficients d31 and d22 in LiNbO3 are of opposite sign, in disagreement with an earlier report by others. This is an important consideration for optimizing nonlinear optical interactions in LiNbO3.
A COMPUTER CALCULATION OF X-RAY DIFFRACTION TOPOGRAPHS FOR DISTORTED CRYSTALS
Authors: Kato Norio , Patel J. R.
Published: January 2004

An outline of a computer calculation for the calculation of Pendellösung fringes in distorted crystals is described. The calculation has been applied to the case of distortion due to a discontinuous oxide film on a silicon substrate, described in the preceding Letter.
STROBOSCOPIC HOLOGRAPHIC INTERFEROMETRY
Authors: Shajenko P. , Johnson C. D.
Published: January 2004

An experimental evaluation of a stroboscopic technique as applied to holographic interferometry is described. This technique is applicable in the analysis of vibrations with high amplitudes and complex wave forms and in the investigation of phase-dependent and nonsymmetrical effects.
SATURATION AND THE TRANSIENT NUTATION EFFECT
Authors: Macomber James D.
Published: January 2004

The relationship between the spectrum of an ensemble saturated by coherent radiation and the forced transient response of that ensemble to the saturating field is derived. An experiment equivalent to the optical analog of the transient nutation effect is proposed.
THE FOCUSING EFFECT INDUCED BY A D–C DRIVEN CdS PLATE
Authors: Wang W. C. , Das P.
Published: January 2004

Various experimental results are reported on the dc-induced optical effects in CdS. Possible explanations are also given.
HIGH POWER QUASI-CW ULTRA-VIOLET ION LASER
Authors: Latimer I. D.
Published: January 2004

A high-power noble gas cw ion laser has been constructed using a tungsten disk structure capable of dissipating over 70 kW of input power. Quasi-continuous laser outputs in the near ultraviolet have been observed at 3638 and 3511 Å of ArIII and true cw output was obtained at 3507, 4067, and 4131 Å of KrIII. The latter has been identified as a new cw laser line. Over one watt of quasi-continuous output was demonstrated with the 3638-Å line. However, high-power continuous output in the uv is limited by serious optical degradation effects.
INFRARED ABSORPTION BANDS IN CARBON- AND OXYGEN-DOPED SILICON
Authors: Vook Frederick L. , Stein Herman J.
Published: January 2004

Infrared absorption measurements were made before and after low-temperature electron irradiations of silicon samples which contained either dispersed oxygen, carbon, or carbon plus oxygen. Two distinctly different centers are formed upon low-temperature irradiation depending upon the carbon and oxygen content. One center is the well-known vacancy-oxygen A-center defect (836 cm−1) and is formed in oxygen-containing silicon with a magnitude which is independent of the carbon content. The other center (922 and 932 cm−1) is formed only in silicon crystals which contain both oxygen and carbon. The results indicate that this center is formed by the trapping of a silicon interstitial at a carbon-oxygen complex.
AMPLIFICATION OF ACOUSTIC WAVES IN A COUPLED SEMICONDUCTOR-PIEZOELECTRIC CERAMIC SYSTEM
Authors: Fischler C. , Yando S.
Published: January 2004

Amplification of longitudinal acoustic waves traveling in a thin piezoelectric ceramic plate was achieved by electrically coupling the elastic waves to the drifting carriers in an n-silicon plate. Amplification up to 15 dB/cm in the 2-MHz range was obtained, and the system was also operated as a tunable oscillator and mixer in the 0.5- to 4-MHz range. In addition, these experiments also enabled us to measure the drift mobility of majority carriers in silicon.
NEW HIGH-GAIN DYNODE FOR PHOTOMULTIPLIERS
Authors: Simon R. E. , Sommer A. H. , Tietjen J. J. , Williams B. F.
Published: January 2004

A new photomultiplier is described in which the recently reported GaP(Cs) material is used for the first dynode to obtain high secondary emission gain. Gain factors of 20 to 40 have been measured resulting in greatly improved performance of the new photomultiplier at very low light levels.
PULSE HEIGHT RESOLUTION OF HIGH GAIN FIRST DYNODE PHOTOMULTIPLIERS
Authors: Morton G. A. , Smith H. M. , Krall H. R.
Published: January 2004

The performance of a new photomultiplier with high-gain GaP(Cs) first dynode is described. The photoelectron statistics are degraded by less than 5% as compared with 20% for conventional multipliers. The improved statistics make it possible, for the first time, to distinguish the emission of one, two, and up to five photoelectrons.
ABSOLUTE MEASUREMENT OF SECOND ORDER NONLINEAR COEFFICIENT FOR OPTICAL GENERATION OF MILLIMETER WAVE DIFFERENCE FREQUENCIES IN GaAs
Authors: Chang T. Y. , VanTran N. , Patel C. K. N.
Published: January 2004

Millimeter wave difference frequencies are generated by mixing adjacent vibrational-rotational lines of CO2 laser in a GaAs-filled waveguide designed for phase matched interactions. Absolute values of the nonlinear coefficient at these frequencies are obtained and are found to be larger than that given by the low-frequency electrooptic coefficient.
INTERFEROMETRIC OBSERVATION OF ABSORPTION INDUCED INDEX CHANGE ASSOCIATED WITH THERMAL BLOOMING
Authors: McLean E. A. , Sica Louis , Glass A. J.
Published: January 2004

The induced index changes associated with thermal blooming have been observed in iodine-doped CCl4 by means of a Mach-Zehnder interferometer. The interference fringe shape next to the window and the temporal growth of the peak fringe displacement at various positions in the cell have been analyzed. Both the conductive and convective stages of thermal blooming are observed.
SINGLE-MODE POWER FROM A 6328 Å LASER INCORPORATING NEON ABSORPTION
Authors: Lee Paul H. , Schoefer Peter B. , Barker W. Benjamin
Published: January 2004

Strong mode-coupling was induced in a long 6328-Å He–Ne laser by the addition of a separate cell containing excited Ne. The resulting single-frequency output power represented most of the total multimode power available. The laser maintained the same mode of oscillation when tuned throughout the entire gain band. This scheme has produced 9.5 mV at a single frequency and was apparently free from any inherent power limitation.
PREFERRED ORIENTATION IN BIAS-SPUTTERED NICKEL CHROMIUM FILMS
Authors: Stern E. , Light T. B.
Published: January 2004

It is shown that substrate bias during dc sputtering effectively reduces oxygen contamination in nichrome films. This in turn leads to an enhancement of the preferred orientation of the deposits. Moreover, it appears that substrate bias plays an additional role in film orientation which is related to the initial nucleation and growth conditions.
PULSE BROADENING IN A MHD COPPER VAPOR LASER
Authors: Asmus J. F. , Moncur N. K.
Published: January 2004

Stimulated emission has been observed from an electrically accelerated copper plasma at 5106 and 5782 Å in a device employing a series of plasma guns which inject the vapor into the laser resonator. In addition to facilitating room temperature operation of a copper laser, this technique provides a flowing active medium which has extended the pulse duration by more than four-fold over that originating from a stationary vapor.
STIMULATED EMISSION FROM CdS AT ULTRA-HIGH CURRENT DENSITY ELECTRON BEAM PUMPING
Authors: Brewster J. L.
Published: January 2004

Stimulated emission to 3 × 108 W/cm3 (about 200-kW peak) have been obtained from CdS platelets, using a 3-nsec, 260-keV electron accelerator. Data are reported from 20 to 1400 A/cm2 at 300°K, and 500 A/cm2 at 77°K showing approximately constant efficiency at points well above threshold.
MICROWAVE PERMITTIVITY OF THE GaAs LATTICE AT TEMPERATURES BETWEEN 100°K AND 600°K
Authors: Lu Tong , Glover Gary H. , Champlin Keith S.
Published: January 2004

An earlier letter reported microwave (70.2 GHz) measurements of the relative permittivity εr of high-resistivity GaAs in the temperature range between 100° and 300°K. This letter extends the measurements to 600°K. Over the entire temperature range 100° < T < 600°K, the permittivity is observed to fit the expression εr(T) = εr(0){1 + αT}, where εr(0) = 12.79 ± 0.10 and α = 1.0 × 10−4 deg−1.
INTERACTION BETWEEN SPIN WAVES AND ELECTRONS IN A HYBRID STRUCTURE OF YIG AND InSb
Authors: Schneider B.
Published: January 2004

The spin-wave power transmission through a hybrid sample of YIG and InSb has been measured as a function of magnetic field strength H0 (0–1500 Oe), frequency f (1.5–4 GHz), and temperature T (150°–340°K). In the range of magnetostatic volume modes, a strong absorption of spin-wave power caused by the electrons in InSb has been found. The magnetic field H* of maximum absorption depends on f and T in a way which can be explained by the assumption of spin-wave-helicon interaction.
PULSED LASER REFLECTION HOLOGRAMS
Authors: Zech R. G. , Siebert L. D.
Published: January 2004

A single-mode pulsed ruby laser was used to record reflection holograms. A photograph of the virtual image of a hologram of one of the authors is shown.
BAND STRUCTURE AND DIRECT TRANSITION ELECTROLUMINESCENCE IN THE In1−xGaxP ALLOYS
Authors: Lorenz M. R. , Reuter W. , Dumke W. P. , Chicotka R. J. , Pettit G. D. , Woodall J. M.
Published: January 2004

The position of the (1, 0, 0) minima in InP are determined from measurements in the region of interconduction band absorption. Direct transition electroluminescence in the In1−xGaxP alloys is observed over a range of alloys up to x = 0.8 and photon energies of up to 2.2 eV at 300°K and is consistent with the bandstructure determined for InP and that of GaP.
OPTICAL HETERODYNE DETECTION AT 10.6 μm OF THE BEAT FREQUENCY BETWEEN A TUNABLE Pb0.88Sn0.12Te DIODE LASER AND A CO2 GAS LASER
Authors: Hinkley E. D. , Harman T. C. , Freed Charles
Published: January 2004

Optical heterodyning between a CO2 gas laser and a current-tunable Pb0.88Sn0.12Te diode laser has been observed with both lasers in CW operation. The beat frequency was tunable from under 50 MHz to 1300 MHz and from 300 MHz to 3500 MHz for heterodyne experiments with the P20 and P18 CO2 laser transitions, respectively.
HIGH-EFFICIENCY OPTICAL PARAMETRIC OSCILLATION AND POWER LIMITING IN LiNbO3
Authors: Kreuzer L. B.
Published: January 2004

Efficiencies of 36% have been observed for the conversion of pumping power to optical parametric oscillator (OPO) output power by pumping with the second harmonic of a pulsed single-mode laser. Previous reports which all used multimode pumps gave a maximum efficiency of about 1%. Unlike oscillators with multimode pumps, field amplitudes were observed to approach steady-state values and the OPO functioned as a power limiter for transmitted pump light. Good agreement has been found between theoretical and experimental conversion efficiencies.
HIGH FIELD CHARACTERISTICS OF Nb3(Al, Ge)
Authors: Hartsough L. D. , Zackay V. F. , Parker E. R.
Published: January 2004

The Jc vs H curve for Nb3(Al0.8Ge0.2) was measured and compared with that of the binary compound Nb3Al. The Nb–Al–Ge alloy curve had a ``peak'' and its resistive critical magnetic field, Hr(J = 0), was above 220 kG at 4.2°K. The composition of the ternary alloy was determined and found to be closer to the ideal 3:1 atomic ratio than that of the binary alloy.
DIRECT MEASUREMENT OF PICOSECOND LIFETIMES
Authors: Scarlet Richard I. , Figueira Joseph F. , Mahr Herbert
Published: January 2004

A lifetime in the picosecond range of a nonradiatively damped electronic transition in an organic dye was measured. The method utilizes picosecond pulses from a Q-switched, mode-locked Nd-glass laser.
OBSERVATION OF MICROSECOND HEAT PULSES IN LARGE MAGNETIC FIELDS
Authors: Wigmore J. K.
Published: January 2004

By means of a new type of heat pulse detector based on the avalanche phenomenon in a doped semiconductor, phonon pulses as short in duration as 0.1 μsec have been studied in magnetic fields up to 30 kOe. Measurements of phonon mean free path as a function of magnetic field have been made in MgO:Fe2+. This detector should make it possible to determine the frequency spectrum of a heat pulse for the first time.
EPITAXIAL SILVER HALIDE FILMS
Authors: Brady L. E. , Castle J. W. , Hamilton J. F.
Published: January 2004

Continuous, oriented films of AgBr and AgCl with either {200} or 111 surfaces can be made, by vacuum deposition, with thicknesses of 0.1 μ or greater. Discontinuous but self-supporting AgI films can also be made, but only in the {111} orientation, and apparently containing some hexagonal as well as cubic AgI. AgBr films have an ionic conductivity that is evidently surface controlled, and is an order of magnitude greater for {111} films than for {200}.
POLARIZATION OF THE LIGHT EMITTED BY A NEODYMIUM-GLASS LASER
Authors: Chartier Germain , Laval René
Published: January 2004

We study the polarization of the light emitted from a Nd-glass laser in isotropic or anisotropic Fabry-Perot resonators. Because of a coupling of orthogonally polarized waves inside the amplifying medium, the laser light is never fully polarized. We describe an experimental arrangement which allows measurements on this coupling during the laser emission. This coupling can be interpreted on the basis of pump-induced stress birefringence; our data are in agreement with those of other authors.
LIGHT EXTINCTION OF LITHIUM TANTALATE IN LIGHT MODULATION
Authors: Sugibuchi Kiyoshi , Tsuya Hideki , Fujino Yoshio
Published: January 2004

A theory for light extinction of LiTaO3 in terms of the nonuniformity of its natural birefringence is presented. The local gradient of the natural birefringence is obtained by observing the fringe pattern appearing on the crystal between crossed polarizers, and the extinction ratios are measured using a He–Ne laser. Agreement between the expected and the observed values is quite good, and simple technique for evaluating the crystal quality for light modulation is established.
VISIBLE CW PARAMETRIC OSCILLATOR
Authors: Byer R. L. , Oshman M. K. , Young J. F. , Harris S. E.
Published: January 2004

A tunable optical parametric oscillator using a 5145-Å argon laser as a pump and lithium niobate as the nonlinear material is reported. The oscillator is constructed in a manner such that the total multimode power of the pumping laser is useful for pumping the oscillator. Operation far from degenerate, combined with a relatively long crystal, leads to measured bandwidths of oscillation about ten times less than those previously reported.
MAGNETOSTRICTIVE GENERATION OF TRANSVERSE MICROWAVE PHONONS WITHOUT EXTERNAL FIELD
Authors: Bialas H. , Weis O.
Published: January 2004

By applying mechanical stresses to evaporated Ni films it is possible to shift the ferromagnetic resonance field to such a low value that even at zero field, transverse phonons at 9.4 GHz are generated by magnetostriction.
THE ENERGY EFFICIENCY OF LEAD SELF-SPUTTERING
Authors: Andersen Hans Henrik
Published: January 2004

The sputtering efficiency (i.e. ratio between sputtered energy and impinging ion energy) has been measured for 30–75-keV lead ions impinging on polycrystalline lead. The results are in good agreement with recent theoretical estimates.
MASS ANALYSIS OF IONS PRODUCED BY HYPERVELOCITY IMPACT
Authors: Hansen D. O.
Published: January 2004

Ions resulting from the impact of hypervelocity microscopic particles upon a solid Ta target have been analyzed by time-of-flight techniques. The impact velocity of the micron-size and smaller, predominately iron particles (∼98% Fe) ranged from 2 to 45 km/sec, which corresponds to an energy range of from 1 to 600 eV/atom. The kinetic energy of the particles is converted into internal energy of an expanding, partially ionized vapor cloud composed of both target and particle material. The energy conversion process occurs on a time scale comparable to that involved in Q-switched laser beam-solid target interactions. In addition to ions of both the bulk target and particle materials, a number of other ion groups are observed which are presumed to be impurities from both the particle and target. A tentative model describing the process is discussed.
PLASMA IMPEDANCE ELEMENT IN AN ACTIVE FABRY-PEROT MICROWAVE RESONATOR
Authors: Ajmera R. C. , Lashinsky H.
Published: January 2004

Experiments are described in which a plasma is used as an impedance element in an active Fabry-Perot microwave resonator which contains a positive feedback loop. The arrangement functions as a Q multiplier or as an oscillator, with the plasma acting as a power or frequency-determining element. The characteristics of the active Fabry-Perot resonator are discussed in connection with diagnostic methods for pulsed and steady-state plasmas.
A NEW ELECTRIC-FIELD-CONTROLLED REFLECTIVE OPTICAL STORAGE EFFECT IN MIXED-LIQUID CRYSTAL SYSTEMS
Authors: Heilmeier George H. , Goldmacher Joel E.
Published: January 2004

A new reflective optical storage effect has been found in mixtures of certain nematic liquid crystals and cholesteric liquid crystals. When subjected to a dc field, the initially clear material becomes milky white and remains in this state when the field is removed. The material can be rapidly switched back to its clear state by an audio-frequency signal. A preliminary model based on the principle of a field-induced emulsion gives rough agreement with experiment.
INTERPRETATION OF HALL AND PHOTO-HALL EFFECTS IN INHOMOGENEOUS MATERIALS
Authors: Bube Richard H.
Published: January 2004

Hall and photo-Hall effects have frequently been used to distinguish between a ``numbers'' mechanism (assumed if Δn ≠ 0 and Δμ = 0), and a ``barier'' mechanism (assumed if Δn = 0 and Δμ ≠ 0) for photoconductivity in possibly inhomogeneous materials. Consideration of a simple model for an inhomogeneous material shows that a wide variety of effects can be obtained in a material with only resistivity variations and without p-n junction barriers. In particular it may be shown that in such a model without barriers, either Δn ≠ 0 and Δμ = 0, or Δn = 0 and Δμ ≠ 0, may be obtained experimentally, depending only on the resistivity ratio between different portions of the material.
A HIGH-RESOLUTION STUDY OF THE C 3Πu → B 3Πg(0, 0) STIMULATED TRANSITIONS IN N*2
Authors: Parks J. H. , Rao D. Ramachandra , Javan A.
Published: January 2004

High-resolution spectroscopy was performed on the C 3Πu → B 3Πg(0, 0) band of N2 using a crossed-grating Echelle spectrograph. The large incremental gain of these transitions produces significant line narrowing which permits wavelength measurements to a relative accuracy of one part in 107. Observed lines have been identified as 27 P branch and 2 R branch transitions distributed among the Π0, Π1, and Π2 spin multiplet sets, and extending from lower level J = 4 to J = 15. Each transition in the Π0 set is observed to originate from the lower Λ component level. A calculation of the relative gain which treats the electron excitation in the optical limit indicates the dominance of these transitions.
FOG DISSIPATION USING A CO2 LASER
Authors: Mullaney G. J. , Christiansen W. H. , Russell D. A.
Published: January 2004

Laboratory measurements have been made of the evaporation rate of fog when subjected to an intensity of 5 to 50 W/cm2 of 10.6-μ radiation. The measurements agree with calculations and show that most of the absorbed laser energy goes into heating the air by conduction from the droplet surface. This heated air induces a motion which prevents the laser from completely clearing the fog. A correlation is found which describes the visibility improvement as the fog and power density are varied.
MEASUREMENT OF THE DIFFUSION OF IRON IN GOLD BY MEANS OF THE MÖSSBAUER EFFECT
Authors: Knauer Robert C. , Mullen James G.
Published: January 2004

Iron diffusion in gold has been measured using the Mössbauer effect. Similar to earlier results on iron diffusion in copper, we find that the broadening of the Mössbauer line is approximately equal to ℏ/τ instead of 2ℏ/τ as predicted by the jump model of diffusion, where τ is the mean life for sitting in a specified lattice site. Since the broadening for both iron diffusion in gold and iron diffusion in copper is approximately a factor of two smaller than predicted theoretically, the results appear to be somewhat general. This lends support to the view that the relaxation of a specified ion out of a lattice site is not a simple exponential in time, as assumed in the theory, but is altered when the vacancy mechanism is responsible for diffusion.
MEASURABLE MAGNETO-OPTICAL CROSS EFFECTS
Authors: Kielich Stanislaw
Published: January 2004

Laser light induces measurable variations in Faraday and Cotton-Mouton effects in isotropic media, particulary large in macromolecular and colloidal substances.
DISLOCATION CONDUCTION AND DECORATION IN POTASSIUM BROMIDE
Authors: Harris L. B.
Published: January 2004

Prolonged application of large uniform electric fields at low (150°C) temperatures to crystals of KBr with silver electrodes causes the silver to decorate dislocations and subgrain boundaries. Charge transport at these temperatures is a highly inhomogeneous process, presumably dominated by dislocation and boundary conduction.
EMPIRICAL RELATIONSHIP BETWEEN SHEAR STRENGTH, PRESSURE, AND TEMPERATURE-II
Authors: Towle Laird C. , Riecker Robert E.
Published: January 2004

The pressure and temperature dependence of the shear strength of grossly deformed solids conforms to a simple empirical law containing two parameters characteristic of the material. The empirical law and the constants appearing in it exhibit an interesting correlation with theoretical calculations of flow stress.
ELECTRON MICROSCOPY OF ORTHORHOMBIC PHASE IN MAGNETITE
Authors: Yamada Toshiro , Suzuki Kunio , Chikazumi Soshin
Published: January 2004

An electron microscopic observation on a synthetic single crystal of magnetite has been carried out at a temperature range between 77°K and room temperature. It was observed that the ordered phases below the low-temperature transition appear as finely divided stripes. The diffraction patterns in one of the stripes show the extra spots such as (00½), (100), (010), or (11½) in cubic indices. This indicates that the unit cell of the low-temperature phase should be twice as large as that proposed by Verwey. The ordering scheme proposed should be more complicated than the Verwey order.
CORRELATION EFFECTS IN THE DISPLAY OF PICOSECOND PULSES BY TWO-PHOTON TECHNIQUES
Authors: Klauder J. R. , Duguay M. A. , Giordmaine J. A. , Shapiro S. L.
Published: January 2004

The two-photon fluorescence (TPF) technique for the display of picosecond pulses is analyzed. It is shown that TPF displays resembling those of picosecond pulses from mode-locked lasers, but having reduced contrast, are produced by lasers in which mode locking is incomplete or absent. We report here new TPF experiments which provide further evidence for picosecond pulse output of dye Q-switched Nd:glass lasers. In addition, TPF observations with a single-mode ruby laser are found to give contrast ratios in agreement with the general theory.
OPTICAL SAMPLING OF SUBNANOSECOND LIGHT PULSES
Authors: Duguay M. A. , Hansen J. W.
Published: January 2004

An optical analog of the electronic sampling oscilloscope is proposed, and preliminary experimental results are presented. The sampling pulses, ∼4 psec in duration, are produced by a mode-locked Nd:glass laser. They are mixed in a KDP crystal with pulses of ∼800-psec duration, from a mode locked He–Ne laser. The optical sum frequency is detected and displayed on a conventional oscilloscope. The pulse separations in the two lasers differ in such a way that, as time goes by, the sampling pulse scans the He–Ne pulse. There results, on the conventional oscilloscope, a sampled display of the He–Ne pulse.
BAND-EDGE SHIFT OF CdCr2Se4 NEAR CURIE TEMPERATURE
Authors: Wen C. P. , Hershenov B. , von Philipsborn H. , Pinch H.
Published: January 2004

It is the purpose of this Letter to present some experimental evidence of the down shift of the conduction band edge when CdCr2Se4 crystals change from the paramagnetic to the ferromagnetic state. The anomalous electrical conductivity versus temperature behavior of indium-doped, n-type CdCr2Se4 is attributed to the movement of the conduction band edge and the resultant free carrier concentration increase in the conduction band. Photovoltaic measurements are made on p-n junctions fabricated on single crystals grown by liquid-transport techniques. The temperature dependence of the optical band gap determined by photovoltaic measurements is in good agreement with absorption measurements reported by Harbeke and Pinch.
MECHANISMS OF ENERGY TRANSPORT BETWEEN RARE-EARTH IONS
Authors: Birgeneau R. J.
Published: January 2004

Recently a series of experiments on the EPR of pairs of coupled rare-earth ions in the light rare-earth halides have been reported. From these experiments it is possible to obtain very detailed information about the mechanisms responsible for nonradiative energy transfer. In particular, it is shown that superexchange is much more effective than normally assumed both in terms of selection rules and range.
THE SURFACE FREE ENERGY OF EMBRYONIC DROPLETS IN THE THEORY OF HOMOGENEOUS NUCLEATION
Authors: Abraham Farid F.
Published: January 2004

In the nucleation theory for water condensation, we argue that the surface tension of an embryonic droplet of water molecules is more nearly approximated by the surface tension of ice than that of liquid water, and this resolves the discrepancy between the Lothe-Pound nucleation theory and experimental observation.