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1.
We report enhanced and broad-band photoluminescence (PL) behavior of C60 doped in porous silica glasses. By carrying out photoluminescence and photoluminescence-excitation spectroscopy of C60 doped in surface-unpassivated and -passivated porous glasses, we show that the interaction of C60 with the silica surface is quite strong and that the modified C60 molecules contribute only in the orange-red region (∼1.9 eV) of the observed PL spectrum. The PL intensity in the blue-green
region (∼2.3 eV) observed in doped glasses is found to originate in the porous glass itself.
Received: 13 July 2000 / Revised version: 24 January 2001 / Published online: 9 May 2001 相似文献
2.
A.B. Djurišić C.Y. Kwong T.W. Lau E.H. Li Z.T. Liu H.S. Kwok L.S.M. Lam W.K. Chan 《Applied Physics A: Materials Science & Processing》2003,76(2):219-223
Optical functions of tris (8-hydroxyquinoline) aluminum (Alq3) have been studied in the spectral range from 1.55 eV to 5 eV using spectroscopic ellipsometry. The samples have been deposited
by thermal evaporation on glass substrates. Optical functions of Alq3 deposited on unheated substrates and on substrates kept at 100 °C have been determined. The optical functions have been modeled
using point-to-point fitting, with the conventional oscillator model and modified oscillator model. It has been found that
point-to-point fitting gives the best agreement with the experimental data, and that the modified oscillator model yields
better agreement with the experimental data than the conventional oscillator model.
Received: 3 September 2001 / Accepted: 22 March 2002 / Published online: 5 July 2002
RID="*"
ID="*"Corresponding author. Fax: +852-2559/8738, E-mail: dalek@eee.hku.hk 相似文献
3.
4.
P. Mierzyński K. Pomorski 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(3):311-314
Strutinsky shell corrections for the cesium-coated fullerenes were investigated. The single particle levels of electrons are
obtained using the spherical mean-field potential of a shifted Wood-Saxon type. The parameters of the potential are adjusted
to reproduce the experimental ionization energies of the Cs(N) clusters and the magic numbers observed in their photo-ionization spectra of the C60Cs(N) aggregates.
Received 24 May 2002 / Received in final form 9 July 2002 Published online 15 October 2002
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ID="*"This work has been partly supported by the Polish Committee for Scientific Research under Contract No. 2P03B 115 19
and by the Program of Scientific Exchange between the IN2P3-France and the Polish Research Institution No. 99-95.
RID="b"
ID="b"e-mail: Krzysztof.Pomorski@umcs.lublin.pl 相似文献
5.
J. Gonzalo O. Sanz A. Perea J.M. Fernández-Navarro C.N. Afonso J. García López 《Applied Physics A: Materials Science & Processing》2003,76(6):943-946
Heavy metal oxide thin films of the ternary system Nb2O5–GeO2–PbO have been prepared by pulsed laser deposition in an O2 environment from either glassy or crystalline bulk samples. The range of ([Pb]+[Nb]) content in which the films are optically
homogeneous and transparent is much broader (0.5–1.0) than that of the bulk samples considered in the present work (0.55–0.62).
The imaginary part of the refractive index is very low in all cases (k<10-3), whereas the real part increases linearly with the ([Pb]+[Nb]) content up to values as high as 2.35. The optical energy
gap has been found to be strongly dependent on [Pb], whereas it is almost independent of [Nb]. This dependence is discussed
in terms of the role of Pb and Nb as network modifiers or formers.
Received: 5 August 2002 / Accepted: 8 August 2002 / Published online: 17 December 2002
RID="*"
ID="*"Corresponding author. Fax: +34-91/564-5557, E-mail: j.gonzalo@io.cfmac.csic.es 相似文献
6.
Y. Liu D. Li R.Y. Zhu G.J. You S.X. Qian Y. Yang J.L. Shi 《Applied physics. B, Lasers and optics》2003,76(4):435-439
Au-core CdS-shell composite nanoparticles were synthesized by a direct self-assembly process and integrated into BaTiO3 thin films. Characterization by transmission electron microscopy showed that the average diameter of these composite nanoparticles
was about 8 nm. Using the femtosecond time-resolved optical Kerr effect method, we investigated the third-order nonlinear
optical response of the Au@CdS nanoparticles embedded in the BaTiO3 thin films at a wavelength of 800 nm. An ultrafast nonlinear response and a large effective third-order nonlinear susceptibility
of χ(3)=7.7×10-11 esu were observed. We attributed the enhancement of the third-order optical nonlinearity to a localized electric field effect
originating from the core-shell structure under off-surface-plasmon resonance conditions.
Received: 13 May 2002 / Revised version: 23 October 2002 / Published online: 3 April 2003
RID="*"
ID="*"Corresponding author. Fax: +86-21/6510-4949, E-mail: sxqian@fudan.ac.cn 相似文献
7.
J.S. Yu J.D. Song J.M. Kim S.J. Bae Y.T. Lee H. Lim 《Applied Physics A: Materials Science & Processing》2003,76(6):979-982
We investigated the effect of rapid thermal annealing (RTA) on the photoluminescence (PL) and electroluminescence of the In0.53Ga0.47As/In0.53(Ga0.6Al0.4)0.47As multiple quantum well (MQW) laser structure with InGaAlAs barrier layers provided by the digital-alloy technique. The SiO2- (Si3N4-) capped samples followed by the RTA exhibited a significant improvement of PL intensity without any appreciable shifts in
PL peak energy for settings of up to 750 °C (800 °C) for 45 s. This improvement is attributed to the annealing of nonradiative
defects in InAlAs layers of digital-alloy InGaAlAs and partially those near the heterointerfaces of the digital-alloy layers.
The InGaAs/InGaAlAs MQW laser diodes fabricated on the samples annealed at 850 °C show a hugely improved lasing performance.
Received: 2 September 2002 / Accepted: 3 September 2002 / Published online: 17 December 2002
RID="*"
ID="*"Corresponding author. Fax: +82-62/970-2204, E-mail: ytlee@kjist.ac.kr 相似文献
8.
Z. Iqbal Y. Zhang H. Grebel S. Vijayalakshmi A. Lahamer G. Benedek M. Bernasconi J. Cariboni I. Spagnolatti R. Sharma F.J. Owens M.E. Kozlov K.V. Rao M. Muhammed 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,31(4):509-515
Evidence is presented for the formation of a solid phase based on the smallest fullerene, C20, in thin diamond-like carbon films deposited by ultraviolet laser ablation from diamond onto nickel substrates at room temperature
in the presence of 10-4 torr of cyclohexane or benzene. Laser desorption mass spectrometry from the films shows the presence of C20, C21 and C22 species, while micro-Raman spectroscopy and electron diffraction from selected particles together with first principle density-functional
calculations, indicate a cubic solid with dodecahedral C20 cages as building blocks. Unlike solid C60 and fully protonated C20, which are bound by van der Waals forces, the proposed structure is stabilized by linking of the C20 dodecahedra with bridging carbon atoms at interstitial tetrahedral sites to form a face-centered-cubic lattice with 22 carbon
atoms per unit cell.
Received 10 October 2002 / Received in final form 24 December 2002 Published online 6 March 2003
RID="a"
ID="a"e-mail: zafar.iqbal@njit.edu 相似文献
9.
V.C. Selvaraju S. Asokan V. Srinivasan 《Applied Physics A: Materials Science & Processing》2003,77(1):149-153
The I–V characteristics of bulk As40Te60-xSex and As35Te65-xSex glasses have been studied with a current sweep of 0–18 mA-0, over a wide range of compositions (4≤x≤22). All the glasses
studied showed a threshold electrical switching behaviour. The number of switching cycles withstood by the samples has been
found to depend on the ON-state current. It is seen that the switching voltages increase with increase in selenium content.
Further, the switching voltages are found to be almost independent of the thickness of the sample (d), in the range 0.18–0.3 mm.
Also, the switching voltages and the number of switching cycles withstood by the samples are found to decrease with temperature.
Received: 6 November 2002 / Accepted: 8 November 2002 / Published online: 29 January 2003
RID="*"
ID="*"Corresponding author. Fax: +91-80/360-0135, E-mail: sasokan@isu.iisc.ernet.in 相似文献
10.
T. Omatsu Y. Ojima B.A. Thompson A. Minassian M.J. Damzen 《Applied physics. B, Lasers and optics》2002,75(4-5):493-495
The high phase-conjugate reflectivity of 150, by four-wave mixing in a diode-pumped Nd:YVO4, has been demonstrated. The phase-conjugate mirror was capable of correcting the phase aberration of a probe beam. The experimental
diffraction efficiency of the transmission gratings was 60.
Received: 8 April 2002 / Revised version: 10 June 2002 / Published online: 25 September 2002
RID="*"
ID="*"Corresponding author. Fax: +81/43-290-3490, E-mail: omatsu@image.tp.chiba-u.ac.jp 相似文献
11.
S.S. Yi J.S. Bae B.K. Moon J.H. Jeong I.W. Kim H.L. Park 《Applied Physics A: Materials Science & Processing》2003,76(3):433-437
ZnGa2O4 thin-film phosphors have been grown on Si(100), Al2O3(0001) and MgO(100) substrates using pulsed laser deposition. The structural characterization was carried out on a series
of ZnGa2O4 films grown on various substrates under various substrate temperatures and oxygen pressures. The films grown on these substrates
not only have different crystallinity and surface morphology, but also different Zn/Ga composition ratio. The crystallinity
and photoluminescence (PL) of the ZnGa2O4 films are highly dependent on the deposition conditions, in particular the stoichiometry ratio of Zn/Ga and the kind of substrate.
The variation of Zn/Ga in the films also depends on not only the oxygen pressure but also the substrate temperature during
deposition. The PL properties of pulsed laser deposited ZnGa2O4 thin films have indicated that Al2O3(0001) and MgO(100) are promising substrates for the growth of high-quality ZnGa2O4 thin films and that the luminescence brightness depends on the substrate. The luminescence spectra show a broad band extending
from 350 to 600 nm and peaking at 460 nm.
Received: 11 July 2002 / Accepted: 31 July 2002 / Published online: 28 October 2002
RID="*"
ID="*"Corresponding author. Fax: +82-51-6206356, E-mail: jhjeong@pknu.ac.kr 相似文献
12.
Results are given for thermal tuning and modulation of a 1556-nm distributed feedback fibre laser by resistive heating of
a thin silver film chemically deposited on the fibre. Without reaching the limits of performance, linear tuning is demonstrated
at a rate of 1.72 pm/mW up to about 200 pm, and a peak-to-peak modulation of 100 MHz up to modulation frequencies of 60 Hz.
The heat flow is analyzed, and the coated fibre is characterized in terms of the static and dynamic wavelength response to
the applied electric power. The performance of the scheme is tested by recording part of the ν1+ν3 combination band spectrum of 13C2H2 with thermal modulation and scanning of the fibre laser.
Received: 12 March 2002 / Revised version: 24 June 2002 / Published online: 25 September 2002
RID="*"
ID="*"Corresponding author. Fax: +45/4593-1137, E-mail: sus@dfm.dtu.dk 相似文献
13.
V.G. Savitski A.M. Malyarevich K.V. Yumashev B.D. Sinclair A.A. Lipovskii 《Applied physics. B, Lasers and optics》2003,76(3):253-256
Diode-pumped Nd:YVO4 and Nd:KGW lasers passively Q-switched with PbS-quantum dot-doped phosphate glass were demonstrated. For the Nd:YVO4 laser, pulses 110 ns in duration with a 13% Q-switching efficiency were obtained. The absorption recovery time of the PbS-doped
glass was measured to be 27±4 ps. Some recommendations for more efficient use of PbS-doped glasses for Q-switching of diode-pumped
lasers are suggested on the basis of our analysis.
Received: 29 July 2002 / Revised version: 18 September 2002 / Published online: 12 February 2003
RID="*"
ID="*"Corresponding author. Fax: +375-17/232-6286, E-mail: savitski@eudoramail.com 相似文献
14.
S.T. Sanders 《Applied physics. B, Lasers and optics》2002,75(6-7):799-802
A swept-wavelength source is created by connecting four elements in series: a femtosecond fiber laser at 1.56 μm, a non-linear
fiber, a dispersive fiber and a tunable spectral bandpass filter. The 1.56-μm pulses are converted to super-continuum (1.1–2.2 μm)
pulses by the non-linear fiber, and these broadband pulses are stretched and arranged into wavelength scans by the dispersive
fiber. The tunable bandpass filter is used to select a portion of the super-continuum as a scan-wavelength output. A variety
of scan characteristics are possible using this approach. As an example, an output with an effective linewidth of approximately
1 cm-1 is scanned from 1350–1550 nm every 20 ns. Compared to previous scanning benchmarks of approximately 1 nm/μs, such broad,
rapid scans offer new capabilities: a gas sensing application is demonstrated by monitoring absorption bands of H2O, CO2, C2H2 and C2H6O at a pressure of 10 bar.
Received: 5 August 2002 / Revised version: 23 September 2002 / Published online: 22 November 2002
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ID="*"Corresponding author. Fax: +1-608/265-2316, E-mail: ssanders@engr.wisc.edu 相似文献
15.
W.Y. Wang D.F. Zhang T. Xu Y.P. Xu T. Zhou B.Q. Hu C.Y. Wang L.S. Wu X.L. Chen 《Applied Physics A: Materials Science & Processing》2003,76(1):71-75
Ca,Ta-doped TiO2 varistors with high nonlinear coefficients are obtained by a ceramic sintering. The nonlinear electrical and dielectric properties
of the samples doped with 0.5mol% Ca and various concentrations of Ta (0.05∼2.0mol%) were investigated. The samples sintered
at 1350 °C have nonlinear coefficients of α=5.1∼42.1 and high relative dielectric constants approach 105. The effects of Ta-doping on the nonlinear and dielectric properties of the Ca,Ta-doped TiO2 varistors are studied in greater detail. When the concentration of Ta is 0.5mol%, the sample possesses the highest nonlinear
coefficient and a comparatively lower dielectric constant. The effects of Ta and the nonlinear electrical behavior of the
TiO2 system are explained by analogy to a grain-boundary atomic defect model.
Received: 24 October 2001 / Accepted: 8 January 2002 / Published online: 3 May 2002
RID="*"
ID="*"Corresponding author. Fax: +86-10/826-49531, E-mail: wangwanyan@yahoo.com.cn 相似文献
16.
Sensitive absorption measurements in the near-infrared region using off-axis integrated-cavity-output spectroscopy 总被引:3,自引:0,他引:3
A novel instrument that employs a high-finesse optical cavity as an absorption cell has been developed for sensitive measurements
of gas mixing ratios using near-infrared diode lasers and absorption-spectroscopy techniques. The instrument employs an off-axis
trajectory of the laser beam through the cell to yield an effective optical path length of several kilometers without significant
unwanted effects due to cavity resonances. As a result, a minimum detectable absorption of approximately 1.4×10-5 over an effective optical path of 4.2 km was obtained in a 1.1-Hz detection bandwidth to yield a detection sensitivity of
approximately 3.1×10-11 cm-1 Hz-1/2. The instrument has been used for sensitive measurements of CO, CH4, C2H2 and NH3.
Received: 6 May 2002 / Revised version: 31 May 2002 / Published online: 2 September 2002
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ID="*"Corresponding author. Fax: +1-650/965-7074, E-mail: d.baer@lgrinc.com 相似文献
17.
The progress in the development of a sensor for the detection of trace air constituents to monitor spacecraft air quality
is reported. A continuous-wave (cw), external-cavity tunable diode laser centered at 1.55 μm is used to pump an optical cavity
absorption cell in cw-cavity ringdown spectroscopy (cw-CRDS). Preliminary results are presented that demonstrate the sensitivity,
selectivity and reproducibility of this method. Detection limits of 2.0 ppm for CO, 2.5 ppm for CO2, 1.8 ppm for H2O, 19.4 ppb for NH3, 7.9 ppb for HCN and 4.0 ppb for C2H2 are calculated.
Received: 3 April 2002 / Revised version: 3 June 2002 / Published online: 21 August 2002
RID="*"
ID="*"Corresponding author. Fax: +1-202/994-5873, E-mail: Houston@gwu.edu 相似文献
18.
S.H. Sun G.W. Meng Y.W. Wang T. Gao M.G. Zhang Y.T. Tian X.S. Peng L.D. Zhang 《Applied Physics A: Materials Science & Processing》2003,76(2):287-289
Tin dioxide (SnO2) nanobelts have been successfully synthesized in bulk quantity by a simple and low-cost process based on the thermal evaporation
of tin powders at 800 °C. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations reveal
that the nanobelts are uniform, with lengths from several-hundred micrometers to a few millimeters, widths of 60 to 250 nm
and thicknesses of 10 to 30 nm. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and selected-area electron
diffraction analysis (SAED) indicate that the nanobelts are tetragonal rutile structure of SnO2. The SnO2 nanobelts grow via a vapor–solid (VS) process.
Received: 3 June 2002 / Accepted: 10 June 2002 / Published online: 10 September 2002
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ID="*"Corresponding author. Fax: +86-551/559-1434, E-mail: gwmeng@mail.issp.ac.cn 相似文献
19.
The ohmic contact characteristics of Au/Pt/Ti on degenerated doped n-GaAs were evaluated. Structural and electrical properties
were studied by means of X-ray diffraction (XRD), Auger Energy Spectrum (AES) and a HP4145B parameter analyzer. The structural
analysis revealed a TiAs phase in the interface between metal multilayer and GaAs at higher annealing temperatures. Electrical
measurement showed a minimum ohmic contact resistance of 3×10-4 Ω cm2. The dominant current mechanism was found to be thermionic emission with a barrier height of Φb, of 0.09 V by comparing the experimental data with different theoretical models.
Received: 14 December 2001 / Accepted: 4 April 2002 / Published online: 22 November 2002
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ID="*"Corresponding author. Fax: +86-21/6226-4397, E-mail: zhoujian999@163.net 相似文献
20.
By optically pumping the deuterated isotopomers of 14NH3 and 15NH3 using 12C16O2, 13C16O2, 12C18O2, and 13C18O2 lasers, several new far-infrared (FIR) emission lines between 65 μm and 125 μm have been detected. The existing spectroscopy
of 14N-ammonia isotopomers has been used to identify many of these lines, as well as some previously observed but unidentified.
The spectroscopic data have been analyzed to predict over 20 additional FIR laser lines that could be pumped by a more capable
CO2 laser. This effort was motivated by a need for strong laser lines in frequency coincidence with molecular transitions of
astrophysical interest. Of particularnote is the measurement of the 2680-GHz line of 14NHD2, whose frequency is 4.9 GHz higher than that of the important J=1-0 line of interstellar HD.
Received: 25 July 2002 / Published online: 20 December 2002
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ID="*"Corresponding author. Fax: +1-303/492-5941, E-mail: boreiko@spot.colorado.edu 相似文献