共查询到20条相似文献,搜索用时 734 毫秒
1.
T.J. Kulp S.E. Bisson R.P. Bambha T.A. Reichardt U.-B. Goers K.W. Aniolek D.A.V. Kliner B.A. Richman K.M. Armstrong R. Sommers R. Schmitt P.E. Powers O. Levi T. Pinguet M. Fejer J.P. Koplow L. Goldberg T.G. McRae 《Applied physics. B, Lasers and optics》2002,75(2-3):317-327
Quasi-phase-matched (QPM) materials allow the generation of spectroscopically useful infrared radiation in an efficient and
broadly tunable format. Here, we describe several applications of QPM-based light sources to remote and local chemical sensing.
The remote systems are gas imagers that employ a fiber-pumped continuous-wave optical parametric oscillator or a microlaser-pumped,
diode-seeded optical parametric amplifier as the illumination source. Technology described for local sensing includes a cavity
ring down spectrometer that employs a novel optical parametric generator–amplifier to achieve ≥350 cm-1 of contiguous tuning and a long-wave infrared light source based on QPM GaAs. In each case the use of QPM materials in conjunction
with effective pump sources instills simplicity and ruggedness into the sensing systems.
Received: 15 April 2002 / Revised version: 6 June 2002 / Published online: 12 September 2002
RID="*"
ID="*"Corresponding author. Fax: +1-925/294-2595, E-mail: tjkulp@sandia.gov
RID="**"
ID="**"Present address: Corning Inc., Corning, NY 14831, USA
RID="*"
ID="*"Present address: Corning Inc., Corning, NY 14831, USA
RID="**"
ID="**"Present address: Blue Leaf Networks, Sunnyvale, CA 94086, USA
RID="***"
ID="***"Present address: Sandia National Laboratories, Albuquerque, NM 87185, USA 相似文献
2.
The use of mid-infrared polarization spectroscopy (PS) for the detection of CO2 has been demonstrated. The P(13) and P(14) resonances of the (0 00 0)→(1 00 1) transition of CO2 were probed using a single-mode optical parametric generator system to produce a high-intensity laser beam at approximately
2.7 μm. The experiments were performed in an atmospheric pressure CO2 jet and also in a sub-atmospheric pressure gas cell. The experimental results were compared with the results of the time-dependent
density-matrix equations using direct numerical integration. The Zeeman-state structure of the upper and lower energy levels
was included in the multi-state formulation of the density-matrix equations. Fifty-eight Zeeman states and two bath levels
were included in the numerical analysis of the P(14) transition. The measured and calculated PS line shapes were in good agreement,
and the absolute experimental signal level agreed with the theoretical calculation to within a factor of five.
Received: 20 March 2002 / Revised version: 16 August 2002 / Published online: 11 December 2002
RID="*"
ID="*"Present address: Innovative Scientific Solutions Inc., 2766 Indian Ripple Road, Dayton, OH 45 440, USA
RID="**"
ID="**"Corresponding author. Fax: +1-765/494-0539, E-mail: Lucht@purdue.edu
RID="***"
ID="***"Present address: School of Mechanical Engineering, Purdue University, W. Lafayette, IN 47807-2040 USA 相似文献
3.
G. Stobrawa M. Hacker R. Netz M. Bischoff R. Sauerbrey 《Applied physics. B, Lasers and optics》2003,76(3):333-336
We present a novel method for measuring the linear and nonlinear dispersion properties of conventional and micro-structured
fibers. It is based on the automated compensation of phase modulations using a high-resolution pulse-shaping device. No tunable
laser source is required.
Received: 20 December 2002 / Published online: 19 March 2003
RID="*"
ID="*"Corresponding author. Fax: +49-3641/947202, E-mail: stobrawa@ioq.uni-jena.de
RID="**"
ID="**"Present address: Carl Zeiss Meditec AG, G?schwitzer Strasse 51–52, 07745 Jena, Germany 相似文献
4.
Sub-nanosecond microchip laser with intracavity Raman conversion 总被引:3,自引:0,他引:3
A.A. Demidovich P.A. Apanasevich L.E. Batay A.S. Grabtchikov A.N. Kuzmin V.A. Lisinetskii V.A. Orlovich O.V. Kuzmin V.L. Hait W. Kiefer M.B. Danailov 《Applied physics. B, Lasers and optics》2003,76(5):509-514
Efficient sub-nanosecond pulse operation of microchip lasers with intracavity Raman conversion and pulse compression is presented
for the first time. The microchip lasers were composed of Nd:LSB or Nd:YAG laser crystals, Cr4+:YAG saturable absorber, and Ba(NO3)2 Raman medium. The pulse duration obtained at the Stokes wavelength (1196 nm) was as short as 118 ps. Optical conversion efficiency
of laser-diode pump power to the Stokes power of 8% was reached. Pulse energy and peak power of Stokes emission were 1.2 μJ
and 5.4 kW, correspondingly. Numerical calculations are in good agreement with obtained experimental results.
Received: 20 December 2002 / Revised version: 6 March 2003 / Published online: 5 May 2003
RID="*"
ID="*"Corresponding author. Fax: +1-716/645-6945, E-mail: ankuzmin@acsu.buffalo.edu
RID="**"
ID="**"Present address: University at Buffalo, SUNY, The Institute for Lasers, Photonics, and Biophotonics, 458 NSC, Buffalo,
NY 14 260-3000, USA 相似文献
5.
T. Ohtsubo T. Azuma M. Takaura T. Higashiguchi S. Kubodera W. Sasaki 《Applied Physics A: Materials Science & Processing》2003,76(2):139-141
We have demonstrated the non-thermal removal of oxygen atoms from an oxidized silicon surface (SiO2) on a silicon wafer by the use of a low-power (0.3 mW cm-2) incoherent vacuum ultraviolet (VUV) light source at 126 nm. X-ray photoelectron spectroscopy (XPS) has shown that a maximum
Si concentration of 80% appears at the surface after a 20-h irradiation with 9.8 eV photons, as a result of oxygen removal
from the SiO2 matrix. The surface morphology, however, indicates no damage or melting on the surface even after the irradiation.
Received: 15 April 2002 / Accepted: 17 April 2002 / Published online: 10 September 2002
RID="*"
ID="*"Permanent address: Nano-Tech Photon Inc., Shimotomita 4132-1, Shintomi, Miyazaki, 889-1404, Japan
RID="**"
ID="**"Corresponding author. Fax: +81-985/583-899, E-mail: kubodera@opt.miyazaki-u.jp 相似文献
6.
R.Kh. Zhukavin D.M. Gaponova A.V. Muravjov E.E. Orlova V.N. Shastin S.G. Pavlov H.-W. Hübers J.N. Hovenier T.O. Klaassen H. Riemann A.F.G. van der Meer 《Applied physics. B, Lasers and optics》2003,76(5):613-616
Terahertz stimulated emission of phosphorus donors in silicon optically excited by radiation from the free-electron laser
FELIX has been studied. It is found that a spectral line of the Si:P laser emission depends on pump frequency. Stimulated
emission arises on the 2p0→1s(E) intra-centre transition (21.2 meV) under resonant pumping of the 2p0 state and on the 2p0→1s(T2) transition (22.3 meV) under pumping of the 2p± or higher odd-parity donor states. The line shift is attributed to the Auger redistribution of the 1s(E)- and 1s(T2)-state populations.
Received: 7 November 2002 / Revised version: 7 April 2003 / Published online: 14 May 2003
RID="*"
ID="*"Corresponding author. Fax: +49-30/6705-55-07, E-mail: sergeij.pavlov@dlr.de
RID="**"
ID="**"On leave from: The Institute for Physics of Microstructures, Nizhny Novgorod, Russia 相似文献
7.
A. Di Lieto P. Minguzzi A. Pirastu S. Sanguinetti V. Magni 《Applied physics. B, Lasers and optics》2002,75(4-5):463-466
A Nd:YVO4 laser, end-pumped by a fiber-coupled diode-laser array, generates 7.3 W of output power at 1342 nm, the highest so far reported
for this host crystal. The slope efficiency is 40% and the output-beam divergence is close to the diffraction limit. An important
point in attaining such results is the choice of crystals with low Nd concentration.
Received: 16 July 2002 / Published online: 25 October 2002
RID="*"
ID="*"Corresponding author. Fax: +39-050/844333, E-mail: dilieto@df.unipi.it
RID="**"
ID="**"Permanent address: Scuola Normale Superiore, Piazza dei Cavalieri 7, Pisa, Italy 相似文献
8.
A.B. Mundt A. Kreuter C. Russo C. Becher D. Leibfried J. Eschner F. Schmidt-Kaler R. Blatt 《Applied physics. B, Lasers and optics》2003,76(2):117-124
We demonstrate coherent coupling of the quadrupole S1/2D5/2 optical transition of a single trapped 40Ca+ ion to the standing wave field of a high-finesse cavity. The dependence of the coupling on temporal dynamics and spatial
variations of the intracavity field is investigated in detail. By precisely controlling the position of the ion in the cavity
standing wave field and by selectively exciting vibrational state-changing transitions the ion’s quantized vibration in the
trap is deterministically coupled to the cavity mode. We confirm coherent interaction of ion and cavity field by exciting
Rabi oscillations with short resonant laser pulses injected into the cavity, which is frequency-stabilized to the atomic transition.
Received: 23 August 2002 / Published online: 8 January 2003
RID="*"
ID="*"Corresponding author. E-mail: christoph.becher@uibk.ac.at
RID="**"
ID="**"Present address: Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305, USA 相似文献
9.
J. Luque R.J.H. Klein-Douwel J.B. Jeffries G.P. Smith D.R. Crosley 《Applied physics. B, Lasers and optics》2002,75(6-7):779-790
Absolute number densities of the CH radical were determined in a partially premixed methane/air flame (equivalence ratio was
1.36) at atmospheric pressure by exciting a predissociating level via the CH B–X(1,0) transition using a quasi-linear laser-induced
fluorescence scheme. The peak number density was (1.0±0.4)×1013 cm-3 or 2.4±1 ppm at 1900 K, with a flame-front width of 250 μm (FWHM). Rotational energy transfer must be considered for correct
laser-induced fluorescence signal interpretation. Competition between optical pumping and rotational relaxation in both excited
and ground states produces a signal that varies almost linearly with laser pulse energy even for large pumping rates. For
these conditions, the population of the initial ground-state rotational level is depleted by optical pumping, and rotational
energy transfer collisions rapidly repopulate the level during the laser pulse. Deviations from linear behavior are less than
20%. The effects of spatial resolution and polarization of the fluorescence on the absolute measurements are also discussed.
Received: 27 March 2002 / Revised version: 22 August 2002 / Published online: 15 November 2002
RID="*"
ID="*"Present address: Lam Research Corporation, Fremont, CA 94538, USA
RID="**"
ID="**"Present address: Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
RID="***"
ID="***"Present address: Mechanical Engineering Dept., Stanford University, Stanford CA 94305, USA
RID="****"
ID="****"Corresponding author. Fax: +1-650/859-6196, E-mail: smith@mplvax.sri.com 相似文献
10.
A.V. Hamza M.W. Newman P.A. Thielen H.W.H. Lee T. Schenkel J.W. McDonald D.H. Schneider 《Applied Physics A: Materials Science & Processing》2003,76(3):313-317
The intense, ultra-fast electronic excitation of clean silicon (100)–(2×1) surfaces leads to the formation of silicon nanostructures
embedded in silicon, which photoluminesce in the yellow-green (∼2-eV band gap). The silicon surfaces were irradiated with
slow, highly charged ions (e.g. Xe44+ and Au53+) to produce the ultra-fast electronic excitation. The observation of excitonic features in the luminescence from these nanostructures
has recently been reported. In this paper we report the dispersion of the excitonic features with laser excitation energy.
A phonon-scattering process is proposed to explain the observed dispersion.
Received: 2 October 2001 / Accepted: 18 July 2002 / Published online: 25 October 2002
RID="*"
ID="*"Corresponding author. Fax: +1-925/423-7040, E-mail: Hamza1@llnl.gov
RID="**"
ID="**"Present address: University of California, Lawrence Berkeley National Laboratory, Berkeley, CA 94 720, USA 相似文献
11.
R.A. Pérez F. Dyment G. García Bermúdez D. Abriola M. Behar 《Applied Physics A: Materials Science & Processing》2003,76(2):247-250
The diffusion of Ta in the hcp (α) phase of high-purity Ti (99.99%) was studied at different temperatures from 911 K up to
1123 K. The Rutherford Backscattering Spectrometry (RBS) and Heavy Ion RBS (HIRBS) techniques were used to obtain the penetration
profiles. The evolution of the diffusion coefficient, D, as a function of temperature follows prediction of the Arrhenius
law. The activation energy of the diffusion process is (318±7)kJ/mol, similar to that corresponding to self-diffusion in α-Ti.
On the other hand, the measured values of D are systematically lower than those corresponding to self-diffusion by a factor
of approximately 5. This reduction could be explained by taking into account the mass difference between Ta and Ti. An increase
of the diffusion coefficient was measured when the diffusion proceeds on a less pure Ti (99.9%) matrix. This increment is
higher at lower temperatures.
Received: 12 November 2001 / Accepted: 12 March 2002 / Published online: 5 July 2002
RID="*"
ID="*"
RID="*"
ID="*"
RID="**"
ID="**"Corresponding author. Fax: +54-11/6772-7362, E-mail: dyment@cnea.gov.ar
RID="*"
ID="*"Members of the Carrera del Investigador Científico del Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET),
Argentina 相似文献
12.
E. Millon J. Perrière R.M. Défourneau D. Défourneau O. Albert J. Etchepare 《Applied Physics A: Materials Science & Processing》2003,77(1):73-80
The elemental composition and the surface morphology of thin films grown by laser ablation of barium titanate with femtosecond
pulses at 620 nm laser wavelength have been systematically studied according to the experimental pulsed-laser deposition parameters
: laser energy density, oxygen pressure, substrate temperature, target–substrate distance and substrate position (in- and
off-axis geometry). Firstly, even at high temperature (700 °C), the deposits consist of coalesced particles up to 1-μm in
size, mixed in a poorly crystallised tetragonal BaTiO3 thin film. The particles formed in femtosecond pulsed-laser deposition induce a high surface roughness, which is observed
whatever the experimental growth conditions and does not correspond to the droplets often observed during laser ablation in
the nanosecond regime. As shown by plasma expansion dynamics, these particles propagate toward the substrate in the plasma
plume with a low velocity, and are assumed to be produced by gas-phase reactions. Moreover, the cationic concentration evaluated
through the Ba/Ti ratio strongly depends on the oxygen pressure in the ablation chamber and the angular position of the substrate
along the normal to the target at laser impact. Indeed, the films appear to be enriched in the heavy element (Ba) when the
substrate is located at high angular deviation. This fact is correlated to an increase in the lighter species (i.e. Ti) in
the central part of the plasma plume.
Received: 30 April 2002 / Accepted: 26 August 2002 / Published online: 8 January 2003
RID="*"
ID="*"Corresponding author. Fax: +33-1/4354-2878, E-mail: millon@gps.jussieu.fr
RID="**"
ID="**"Also at: LSMCL, Université de Metz, 57078 Metz Cedex 3, France 相似文献
13.
A high-sensitivity in situ optical diagnostic technique for laser cleaning of transparent substrates
N. Chaoui J. Solis C.N. Afonso T. Fourrier T. Muehlberger G. Schrems M. Mosbacher D. Bäuerle M. Bertsch P. Leiderer 《Applied Physics A: Materials Science & Processing》2003,76(5):767-771
A differential optical transmission technique has been used to monitor in situ the efficiency of laser cleaning for the removal
of sub-micrometer-sized particles on substrates transparent at the monitoring wavelength. This technique has been applied
to the removal of sub-micrometer polystyrene particles on polyimide substrates using laser pulses of 30 ps duration at 292 nm
while probing the material transmission at 633 nm. The sensitivity achieved -1/104 for the transmission changes induced upon single-pulse laser exposure – allows us to monitor the removal of just a few sub-micron-sized
particles from the probed region inside the irradiated area.
Received: 2 October 2002 / Accepted: 7 October 2002 / Published online: 29 January 2003
RID="*"
ID="*"Corresponding author. Fax: +33-3/87844082, E-mail: nchaoui@iut.univ-metz.fr
RID="**"
ID="**"Present address: Laboratoire de Chimie et Applications, Institut Universitaire de Technologie de Metz, Département
Chimie, Rue Victor Demange, 57500 Saint-Avold, France 相似文献
14.
A versatile CO laser-based photoacoustic spectrometer is presented equipped with three photoacoustic cells placed inside the
laser cavity. The newly designed CO laser can operate both in the Δv=1 and the Δv=2 modes (5.1–8.0 μm and 2.8–4.1 μm) on 400
laser lines. Improved laser operation originating from a better cooling of the gas discharge was evidenced by a shift of the
laser output power to lower J-values. Due to the wide emission range of the source, many molecules of biological and atmospheric
interest, including methane and ethane, can be detected with sensitivities typically at the (sub)ppb level. Measurement of
the respiration of a cockroach showed that the spectrometer is not only sensitive, but also has a good time response (8 s
at a flow rate of 10 l/h).
Received: 3 April 2002 / Revised version: 14 June 2002 / Published online: 21 August 2002
RID="*"
ID="*"Current address: Soegijapranata Catholic University, Department of Food Technology, Jalan Pawiyatan Luhur IV/1 Bendan
Duwur, P.O. Box 8033/SM, Semarang 50234, Indonesia
RID="**"
ID="**"Current address: Sanata Dharma University, FMIPA, Kampus III, Paingan, Maguwoharjo, Depok, Sleman, Tromol Pos 29, Yogyakarta
55002, Indonesia
RID="***"
ID="***"Corresponding author. Fax: +31-24/365-3311, E-mail: fransh@ sci.kun.nl 相似文献
15.
X. Zhu S. Lu H.L.W. Chan C.L. Choy K.H. Wong 《Applied Physics A: Materials Science & Processing》2003,76(2):225-229
Compositionally graded (Ba1-xSrx)TiO3 (BST) (x:0.0∼0.25) thin films were grown on Pt (111)/TiO2/SiO2/Si (100) substrates using layer-by-layer pulsed laser deposition in the temperature range 550–650 °C. Both downgraded (Ba/Sr
ratio varying from 100/0 at the bottom surface to 75/25 at the top surface) and upgraded (Ba/Sr ratio varying from 75/25 at
the bottom surface to 100/0 at the top surface) BST films were prepared. Their microstructures were systematically studied
by X-ray diffractometry and scanning electron microscopy. A grain morphology transition from large ‘rosettes’ (>0.30 μm) to
small compact grains (70–110 nm) was observed in the downgraded BST films as the deposition temperature was increased from
550 to 650 °C. No such grain morphology transition was detected in the upgraded BST films. Dielectric measurements with metal
electrodes revealed an enhanced dielectric behavior in the downgraded films. This enhancement is mainly attributed to the
large compressive stress field built up near the interface between the downgraded film and substrate. Furthermore, the BaTiO3 layer in the downgraded BST films not only serves as a bottom layer but also as an excellent seeding layer for enhancing
the crystallization of the subsequent film layers in the downgraded films.
Received: 10 December 2001 / Accepted: 12 March 2002 / Published online: 19 July 2002
RID="*"
ID="*"Corresponding author. Fax: 86-25/359-5535, E-mail: xhzhu@public1.ptt.js.cn 相似文献
16.
E. Gehrig O. Hess C. Seibert D. Woll R. Wallenstein 《Applied physics. B, Lasers and optics》2003,76(3):285-288
We theoretically describe and experimentally investigate the spatio-spectral wave mixing of induced and spontaneous emission
in large-area InGaAs-semiconductor laser amplifiers. The dynamic light-matter-coupling is described by a spatially resolved
theory based on Maxwell–Bloch–Langevin equations, taking into account many-body-carrier interactions, energy transfer between
the carrier and phonon systems and, in particular, the spatio-temporal interplay of stimulated and amplified spontaneous emission
and the noise caused by spontaneous emission. Our numerical model reveals the fundamental physical processes which are responsible
for the spectral power distribution of the amplified laser light and predicts the emission properties of high-power semiconductor
laser amplifiers, such as emission spectra and input power–output power characteristics.
Received:30October2002/Revisedversion:21November2002 / Published online: 12 February 2003
RID="*"
ID="*"Corresponding author. Fax: +49-711/6862-349, E-mail: Edeltraud.Gehrig@dlr.de
RID="**"
ID="**"Also at: Institute of Physics, Tampere University of Technology, P.O. Box 692, FIN-33101, Tampere, Finland
RID="***"
ID="***"Present address: Heidelberger Druckmaschinen AG, Speyerer Strasse 6, 69115 Heidelberg, Germany
RID="****"
ID="****"Present address: Lightbit Corporation, 411 Clyde Avenue, Mountain View, CA 94043, USA 相似文献
17.
We examine in detail the theory of the intrinsic non-linearities in the dynamics of trapped ions due to the Coulomb interaction.
In particular, the possibility of mode–mode coupling, which can be a source of decoherence in trapped ion quantum computation,
or can be exploited for parametric down-conversion of phonons, is discussed and conditions under which such coupling is possible
are derived.
Received: 8 November 2002 / Published online: 26 March 2003
RID="*"
ID="*"Permanent address: MIP, Université Pierre et Marie Curie and Département de Physique, école Normale Supérieure, 75005
Paris, France
RID="**"
ID="**"Corresponding author. Fax: +1-505/667-1931, E-mail: dfvj@lanl.gov 相似文献
18.
R.A. Ganeev R.I. Tugushev A.A. Ishchenko N.A. Derevyanko A.I. Ryasnyansky T. Usmanov 《Applied physics. B, Lasers and optics》2003,76(6):683-686
We investigated nonlinear refraction, nonlinear absorption, and saturable absorption of polymethine dyes by the Z-scan technique
(λ=1064 nm). The analysis of simultaneous appearance of several nonlinear optical processes in dye solutions excited by picosecond
pulses was carried out. The saturable absorption was analyzed taking into account various models. Nonlinear refractive indices,
nonlinear absorption coefficients, and saturation intensities of various polymethine dyes were measured.
Received: 27 December 2002 / Revised version: 6 March 2003 / Published online: 5 May 2003
RID="*"
ID="*"Corresponding author. Fax: +81-471/363-366, E-mail: r_ganeev@issp.u-tokyo.ac.jp
RID="**"
ID="**"Present address: The Institute for Solid State Physics, The Tokyo University, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581,
Japan 相似文献
19.
K.P. Unnikrishnan J. Thomas V.P.N. Nampoori C.P.G. Vallabhan 《Applied physics. B, Lasers and optics》2002,75(8):871-874
The wavelength dependence of the nonlinear absorption of a bis-phthalocyanine, Nd(Pc)2, dissolved in dimethyl formamide was studied in the rising part of the Q-band using the open aperture Z-scan technique, to
determine the wavelength region over which the nonlinear absorption changes from reverse saturable absorption to saturable
absorption. It was found that the sample could be used as a reverse saturable absorber, and hence as an optical limiter, up
to a wavelength of about 604 nm. The imaginary part of the third order susceptibility was also calculated for these wavelengths.
Resonant enhancement of the imaginary part of the third order susceptibility was clearly observed.
Received: 26 April 2002 / Revised version: 30 June 2002 / Published online: 20 December 2002
RID="*"
ID="*"Corresponding author. Fax: +91-484/576-714, E-mail: kpu@cusat.ac.in
RID="**"
ID="**"Present address: Optical Sciences Center, University of Arizona, Tucson, USA 相似文献
20.
N. Navi H. Kim J.S. Horwitz H.D. Wu S.B. Qadri 《Applied Physics A: Materials Science & Processing》2003,76(5):841-846
The structural and the microwave dielectric properties of BaxSr(1-x)TiO3 films (BST) with x=0.5, 0.6 and 0.7, containing 1 mol % W have been investigated. The films were grown by pulsed-laser deposition
on MgO (001) substrates at a temperature of 720 °C in an oxygen pressure from 3 to 500 mTorr. The film structures were determined
by X-ray diffraction. The lattice parameters were fitted to a tetragonal distortion of a cubic lattice. The out-of-plane lattice
parameter (c) was calculated from the position of the (004) reflection. Using c, the in-plane lattice parameter, a, was calculated
from the position of the (024) and (224) reflections. A deviation in the calculated values for a, beyond the systematic error,
was found in the in-plane lattice parameter, suggesting an in-plane orthorhombic distortion (a, a’). Films with x=0.7 showed
a minimum in-plane distortion due to a better lattice match with the substrate. The ratio of the in-plane and out-of-plane
lattice parameters was calculated as a measure of the lattice distortion (a/c and a’/c). The dielectric properties of the
films deposited were measured at room temperature at 2 GHz using gap capacitors fabricated on top of the dielectric film.
For all Ba/Sr ratios investigated in the W-doped material, the dielectric Q (1/cosδ) was observed to be insensitive to the
oxygen deposition pressure. A peak in the change in the dielectric constant, as a function of an applied electric field (0–80 kV/cm),
was observed for films deposited in 50 mTorr of oxygen. The largest K-factor, K=(ε(0)-ε(V )/ε(0)×Q(0)), for films deposited
from a BST x=0.6 (1 mol % W-doped) target was observed in the film that had a minimum in-plane strain, where a∼a’ and c was
greater than a and a’.
Received: 4 July 2002 / Accepted: 5 July 2002 / Published online: 17 December 2002
RID="*"
ID="*"Permanent address: Nuclear Research Center–Negev, P.O. Box 9001 Beer-Sheva, Israel
RID="**"
ID="**"Corresponding author. Fax: +1-202/767-5301, E-mail: horwitz@ccsalpha3.nrl.navy.mil 相似文献