共查询到20条相似文献,搜索用时 15 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
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ID="*"Corresponding author. Fax: +1-925/294-2595, E-mail: tjkulp@sandia.gov
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ID="**"Present address: Corning Inc., Corning, NY 14831, USA
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ID="*"Present address: Corning Inc., Corning, NY 14831, USA
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ID="**"Present address: Blue Leaf Networks, Sunnyvale, CA 94086, USA
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ID="***"Present address: Sandia National Laboratories, Albuquerque, NM 87185, USA 相似文献
2.
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
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ID="*"Permanent address: MIP, Université Pierre et Marie Curie and Département de Physique, école Normale Supérieure, 75005
Paris, France
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ID="**"Corresponding author. Fax: +1-505/667-1931, E-mail: dfvj@lanl.gov 相似文献
3.
C. Affolderbach M. Stähler S. Knappe R. Wynands 《Applied physics. B, Lasers and optics》2002,75(6-7):605-612
Optical magnetometers have reached sensitivities that make them interesting candidates for the measurement of weak magnetic
fields also outside physics laboratories. In order to overcome problems with stray magnetic fields a common solution with
existing magnetometers is to operate a pair of them in a gradiometer configuration: one sensor measures the signal plus the
stray fields, while the other one is mounted such that it is only influenced by the stray fields. In the difference signal
the stray fields cancel. We have constructed such a gradiometer consisting of two sensors based on coherent population trapping
(CPT) resonances in a thermal cesium vapor. Using a magnetic bias field the intrinsically scalar CPT magnetometer can be turned
into a true vector magnetometer that is insensitive to magnetic fields perpendicular to a chosen measurement direction. We
describe how to align and calibrate the gradiometer. Stray field suppression by more than two orders of magnitude has been
achieved, limited by the sensitivity of the magnetometer. This makes possible the detection of picotesla flux density changes
in a weakly shielded or even unshielded environment.
Received: 3 April 2002 / Published online: 15 November 2002
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ID="*"New address: Département de Physique, Université de Fribourg, Chemin du Musée 3, 1700 Fribourg, Switzerland
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ID="**"Corresponding author. Fax: +41-26/300-9631, E-mail: robert.wynands@unifr.ch 相似文献
4.
Wilpers G. Degenhardt C. Binnewies T. Chernyshov A. Riehle F. Helmcke J. Sterr U. 《Applied physics. B, Lasers and optics》2003,76(2):149-156
We have investigated the two major effects that limit the accuracy of an optical frequency standard based on laser-cooled
neutral calcium atoms, i.e. the residual Doppler shift and atomic collisions. A new correction method was applied to reduce
the contribution of the residual Doppler effect to the total fractional uncertainty to 1×10-14. Measurements of the shift of the clock transition frequency due to cold collisions allowed us to reduce their contribution
to 4×10-15. With these improvements we have reduced the total fractional frequency uncertainty of the standard by nearly an order of
magnitude to 2×10-14.
Received: 9 August 2002 / Revised version: 16 November 2002 / Published online: 26 February 2003
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ID="*"Permanent address: Russian Academy of Sciences, P.N. Lebedev Physical Institute, Samara Branch, Novo-Sadovaya st. 221,
Samara 443011, Russia
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ID="**"Corresponding author. Fax: +49-531/592-4305, E-mail: uwe.sterr@ptb.de 相似文献
5.
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
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ID="*"Corresponding author. Fax: +49-711/6862-349, E-mail: Edeltraud.Gehrig@dlr.de
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ID="**"Also at: Institute of Physics, Tampere University of Technology, P.O. Box 692, FIN-33101, Tampere, Finland
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ID="***"Present address: Heidelberger Druckmaschinen AG, Speyerer Strasse 6, 69115 Heidelberg, Germany
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ID="****"Present address: Lightbit Corporation, 411 Clyde Avenue, Mountain View, CA 94043, USA 相似文献
6.
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
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ID="*"Permanent address: Nano-Tech Photon Inc., Shimotomita 4132-1, Shintomi, Miyazaki, 889-1404, Japan
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ID="**"Corresponding author. Fax: +81-985/583-899, E-mail: kubodera@opt.miyazaki-u.jp 相似文献
7.
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
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ID="**"Corresponding author. Fax: +54-11/6772-7362, E-mail: dyment@cnea.gov.ar
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ID="*"Members of the Carrera del Investigador Científico del Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET),
Argentina 相似文献
8.
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
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ID="*"Corresponding author. Fax: +49-3641/947202, E-mail: stobrawa@ioq.uni-jena.de
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ID="**"Present address: Carl Zeiss Meditec AG, G?schwitzer Strasse 51–52, 07745 Jena, Germany 相似文献
9.
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
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ID="*"Corresponding author. Fax: +33-3/87844082, E-mail: nchaoui@iut.univ-metz.fr
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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
10.
L. Nedelchev L. Nikolova A. Matharu P.S. Ramanujam 《Applied physics. B, Lasers and optics》2002,75(6-7):671-676
A study of the propagation of elliptically polarized light and the resulting formation of macroscopic chiral structures in
a series of azobenzene side-chain copolyesters, in which the morphology is varied from liquid crystalline to amorphous, is
reported. Real-time measurements are presented, showing the dynamic behavior of the photoinduced rotation of the polarization
ellipse in the different samples. The relationship between the ellipticity of the recording light and the linear birefringence
induced is studied. A numerical solution that takes into account the influence of the photoinduced linear dichroism on the
light propagation through the samples is presented.
Received: 10 June 2002 / Revised version: 26 July 2002 / Published online: 15 November 2002
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ID="*"Corresponding author. Fax: +45-4677/4588, E-mail: lian.nedelchev@risoe.dk
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ID="**"Permanent address: Department of Chemistry and Physics, The Nottingham Trent Unversity, Clifton Lane, Nottingham NG11 8NS,
England 相似文献
11.
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
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ID="*"Present address: Lam Research Corporation, Fremont, CA 94538, USA
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ID="**"Present address: Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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ID="***"Present address: Mechanical Engineering Dept., Stanford University, Stanford CA 94305, USA
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ID="****"Corresponding author. Fax: +1-650/859-6196, E-mail: smith@mplvax.sri.com 相似文献
12.
A. Borowiec M. MacKenzie G.C. Weatherly H.K. Haugen 《Applied Physics A: Materials Science & Processing》2003,76(2):201-207
The final state of the material resulting from laser irradiation of silicon using 130 fs pulses at 790 nm was studied using
a number of techniques including scanning and transmission electron microscopies, as well as atomic force microscopy. Structural
details and the level of damage to the nearby solid following irradiation were characterized and are discussed in the context
of recent dynamical studies.
Received: 28 September 2001 / Accepted: 3 March 2002 / Published online: 19 July 2002
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ID="*"Department of Engineering Physics, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
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ID="**"Corresponding author. Fax: +1-905/521-2773, E-mail: borowia@mcmaster.ca
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ID="***"Present address: Department of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK
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ID="****"Department of Materials Science and the CEMD, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
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ID="*****"Departments of Engineering Physics, and Physics and Astronomy, and the CEMD, McMaster University, Hamilton, Ontario,
L8S 4M1, Canada 相似文献
13.
Bulk heating of transparent materials using a high-repetition-rate femtosecond laser 总被引:7,自引:0,他引:7
C.B. Schaffer J.F. García E. Mazur 《Applied Physics A: Materials Science & Processing》2003,76(3):351-354
Femtosecond laser pulses can locally induce structural and chemical changes in the bulk of transparent materials, opening
the door to the three-dimensional fabrication of optical devices. We review the laser and focusing parameters that have been
applied to induce these changes and discuss the different physical mechanisms that play a role in forming them. We then describe
a new technique for inducing refractive-index changes in bulk material using a high-repetition-rate femtosecond oscillator.
The changes are caused by a localized melting of the material, which results from an accumulation of thermal energy due to
nonlinear absorption of the high-repetition-rate train of laser pulses.
Received: 21 November 2001 / Accepted: 9 July 2002 / Published online: 25 October 2002
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ID="*"Corresponding author. Fax: +1-858/534-7697, E-mail: cschaffer@ucsd.edu
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ID="**"Current address: University of California, San Diego, Department of Physics, La Jolla, CA 92 093, USA 相似文献
14.
M. Pons S. Nonell I. García-Moreno Á. Costela R. Sastre 《Applied physics. B, Lasers and optics》2002,75(6-7):687-694
A dual-beam pulsed-laser time-resolved thermal lens (TRTL) has been used to study the heat dissipation effects in solid polymers
employed as laser dyes. The laser-dye samples studied are polymer solutions of rhodamine 6G (Rh6G), namely homopolymers of
methyl methacrylate (MMA) and copolymers of methyl methacrylate and 2-hydroxyethyl methacrylate (HEMA) with MMA:HEMA compositions
1:1 and 7:3 vol./vol., where the dye is either dissolved or modified and copolymerized with methacrylate monomers. The long-term
stability of the laser material is independent of the thermal diffusivity of the samples, as determined by the TRTL technique.
This suggests that the rate of heat dissipation does not play a major role in the photostability of the samples. In contrast,
the TRTL experiments have revealed permanent changes in the optical properties of the polymers when subjected to a large number
of laser pulses. This is explained in terms of permanent plastic deformation of the matrices.
Received: 19 June 2002 / Revised version: 1 August 2002 / Published online: 15 November 2002
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ID="*"Dedicated to Prof. S.E. Braslavsky on the occasion of her 60th birthday. This work was presented at the V Congreso de
Fotoquímica, Torremolinos, Spain, 2001
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ID="**"Corresponding author. Fax: +34-93/205-6266, E-mail: s.nonell@iqs.es 相似文献
15.
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
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ID="*"Corresponding author. E-mail: christoph.becher@uibk.ac.at
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ID="**"Present address: Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305, USA 相似文献
16.
17.
V. Shutthanandan J. Zhang P. Ray 《Applied Physics A: Materials Science & Processing》2003,76(7):1093-1097
Silver, copper, and boron (from a boron nitride target) were sputtered with xenon ions. The isotopic composition of secondary
ions of silver was measured at ion energies ranging from 300 eV to 3 keV and, for copper and boron, at 2.0, 2.5, and 3.0 keV.
An ion gun was used to generate the ion beam. The secondary ions were detected at a small emission angle by a quadrupole mass
spectrometer. The secondary-ion flux of silver was found to be enriched in heavy isotopes at lower incident-ion energies.
The heavy-isotope enrichment was observed to decrease with increasing primary-ion energy. Beyond 500 eV, light isotopes of
silver were sputtered preferentially with the enrichment increasing to a constant value of 1.018. The sputtered flux of copper
and boron also indicated constant enrichments (1.008 and 1.281 for copper and boron respectively) in light isotopes at high
ion energies.
Received: 2 August 2002 / Accepted 9 August 2002: / Published online: 4 December 2002
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ID="*"Present address: Pacific Northwest National Laboratory, Richland, WA 99 352, USA
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ID="**"Present address: Philips Display Components Company, Ottawa, OH 45 875 USA
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ID="***"Corresponding author. Fax: +1-334/727-8090, E-mail: pkray@tusk.edu 相似文献
18.
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
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ID="*"Corresponding author. Fax: +39-050/844333, E-mail: dilieto@df.unipi.it
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ID="**"Permanent address: Scuola Normale Superiore, Piazza dei Cavalieri 7, Pisa, Italy 相似文献
19.
Ch. Schwedes E. Peik J. von Zanthier A.Y. Nevsky H. Walther 《Applied physics. B, Lasers and optics》2003,76(2):143-147
A compact, tunable and narrow-bandwidth laser source for blue and ultraviolet radiation is presented. A grating-stabilized
diode laser at 922 nm is frequency-stabilized to below 100 Hz relative to a reference resonator. Injection of the diode-laser
light into a tapered amplifier yields a power of 0.5 W. In a first frequency-doubling stage, more than 200 mW of blue light
at 461 nm is generated by use of a periodically poled KTP crystal. Subsequent second-harmonic generation employing a BBO crystal
leads to about 1 mW of ultraviolet light at 231 nm.
Received: 12 August 2002 / Published online: 15 January 2003
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ID="*"Corresponding author. Fax: +49-89/32905-200, E-mail: christian.schwedes@mpq.mpg.de
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ID="**"Present address: PTB, Bundesallee 100, 38116 Braunschweig, Germany 相似文献
20.
J. Guéna E. Jahier M. Lintz A. Papoyan S. Sanguinetti M.A. Bouchiat 《Applied physics. B, Lasers and optics》2002,75(6-7):739-743
We observe charge multiplication of photoemitted electrons in cylindrical alumina cells, containing cesium vapor, submitted
to a longitudinal electric field and to intense laser pulses. We present several diagnoses allowing us to attribute this charge
multiplication to efficient secondary electron emission (SEE) from the accelerated photoelectrons colliding with the inner
wall at grazing incidence. Machining millimeter-size triangular grooves on the initially smooth inner wall, so as to prevent
grazing incidence, is shown to be efficient in reducing SEE. The atomic signal characteristic of the space charge accumulated
close to the anode is found to be reduced by more than one order of magnitude. This result is of important significance, not
only for our parity-violation experiment in cesium vapor, but also for experiments and techniques involving SEE at grazing
incidence.
Laboratoire de l’Ecole Normale Supérieure associé au CNRS (UMR 8552) et à l’Université Pierre et Marie Curie.
Received: 25 June 2002 / Revised version: 11 September 2002 / Published online: 15 November 2002
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ID="*"Present address: Institute for Physical Research, Ashtarak-2, 378 410 Armenia.
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ID="**"Corresponding author. Fax: +33-1/4432-3434, E-mail:marianne@lkb.ens.fr 相似文献