共查询到20条相似文献,搜索用时 15 毫秒
1.
E. Ambite D. Balboa J. L. Plaza L. Arizmendi 《Applied physics. B, Lasers and optics》2009,95(3):447-452
We have investigated the properties of thermally fixed holograms in LiNbO3 crystals doped with the optical damage inhibitor Zn as well as the photorefractive Fe dopants. Time decays of fixed holograms
at different temperatures showed a single thermally activated process with an activation energy of ∼1.08 eV. We have also
studied the effect of an external electric field on the diffraction efficiency of these holograms. Results analysis has provided
a new method to determine the photovoltaic field of the samples as well as the effective concentration of photorefractive
traps. 相似文献
2.
The absorption spectra, fluorescence spectrum and fluorescence decay curve of Nd3+ ions in CaNb2O6 crystal were measured at room temperature. The peak absorption cross section was calculated to be 6.202×10−20 cm2 with a broad FWHM of 7 nm at 808 nm for E//a light polarization. The spectroscopic parameters of Nd3+ ions in CaNb2O6 crystal have been investigated based on Judd-Ofelt theory. The parameters of the line strengths Ω
t
are Ω
2=5.321×10−20 cm2,Ω
4=1.734×10−20 cm2,Ω
6=2.889×10−20 cm2. The radiative lifetime, the fluorescence lifetime and the quantum efficiency are 167 μs, 152 μs and 91%, respectively. The fluorescence branch ratios are calculated to be β
1=36.03%,β
2=52.29%,β
3=11.15%,β
4=0.533%. The emission cross section at 1062 nm is 9.87×10−20 cm2. 相似文献
3.
N. Coluccelli G. Galzerano L. Bonelli A. Toncelli A. Di Lieto M. Tonelli P. Laporta 《Applied physics. B, Lasers and optics》2008,92(4):519-523
We present a comparative analysis on the growth, the spectroscopic features, and the cw laser action of room-temperature Yb(5%):LiYF4 (YLF) and Yb(10%):KYF4 (KYF) crystals. Optical slope efficiencies of 33% and 52% have been demonstrated for Yb:YLF and Yb:KYF crystals, respectively.
A remarkable wide wavelength tunability from 1.01 to 1.07 μm has been obtained for both laser crystals. 相似文献
4.
V. K. Rai 《Applied physics. B, Lasers and optics》2009,95(2):329-333
Upconversion luminescence in triply ionized praseodymium-doped TeO2–Li2O glass using excitation at ∼590 nm into the 1D2 level from a dye laser pumped with the second harmonic of a pulsed Nd:YAG laser has been reported. The mechanism involved
in the upconversion emission observed at ∼480 nm indicates that the most important contribution is energy transfer among praseodymium
ions in pairs followed by the dipole–dipole interaction. The rate-equation model for the emission at ∼480 nm that provides
direct information to determine the energy-transfer rates containing the pair of states involved in the upconversion process
has been explored. 相似文献
5.
L. Kovács M. Mazzera E. Beregi R. Capelletti 《Applied physics. B, Lasers and optics》2009,94(2):273-277
Several weak absorption bands have been observed in the optical absorption spectra of pure and rare-earth-doped YAl3(BO3)4 single crystals in the 3350– 3650 cm−1 wave number region. Two of them, peaking at about 3377 cm−1 and 3580 cm−1 in the 8 K spectra, appear in most of the samples. They are tentatively attributed to the stretching mode of OH− ions incorporated in the crystal during the growth. An additional absorption band at about 5250 cm−1 at 8 K has also been detected in almost all samples. The temperature and polarization dependences of these bands, and their
possible origin, are discussed. 相似文献
6.
I. V. Kedyk P. Mathey G. Gadret A. A. Grabar K. V. Fedyo I. M. Stoika I. P. Prits Y. M. Vysochanskii 《Applied physics. B, Lasers and optics》2008,92(4):549-554
In this work we report results on electro-physical, optical and photorefractive investigations for Sb-doped Sn2P2S6 crystals. The crystals are obtained by two methods: the vapour-transport technique and the Bridgman technique using stoichiometric
Sn2P2S6 composition with different amounts of antimony in the initial compound. The good optical quality of the crystals obtained
with the Bridgman technique is underlined. The dependences of the photorefractive two-beam coupling coefficient and the grating
build-up time are investigated at the wavelength of 633 nm. It is found that the sample doped with 1.5% of Sb is characterized
by an optimal combination of the main photorefractive parameters exhibiting a fairly high two-beam coupling coefficient (up
to 20 cm−1) and a short response time (1.3 ms) that is the shortest among all the previously studied Sn2P2S6 crystals in the red spectral region. 相似文献
7.
Tingyin Ning Cong Chen Yueliang Zhou Heng Lu Dongxiang Zhang Hai Ming Guozhen Yang 《Applied Physics A: Materials Science & Processing》2009,94(3):567-570
CaCu3Ti4O12 (CCTO) thin films were successfully prepared on LaAlO3 substrates by pulsed laser deposition technique. We measured the nonlinear optical susceptibility of the thin films using
Z-scan method at a wavelength of 532 nm with pulse durations of 25 ps and 7 ns. The large values of the third-order nonlinear
optical susceptibility, χ
(3), of the CCTO film were obtained to be 2.79×10−8 esu and 3.30×10−6 esu in picosecond and nanosecond time regimes, respectively, which are among the best results of some representative nonlinear
optical materials. The origin of optical nonlinearity of CCTO films was discussed. The results indicate that the CCTO films
on LaAlO3 substrates are promising candidate materials for applications in nonlinear optical devices. 相似文献
8.
Kun Yin Hui Xu Gaoyu Zhong Gang Ni Wei Huang 《Applied Physics A: Materials Science & Processing》2009,95(2):595-600
A novel europium complex Eu(TTA)3(CPPO)2 (1) (TTA=thenoyltrifluoroacetone, CPPO=9-[4-(diphenyl-phosphinoyl)-phenyl]-9H-carbazole) based on the phosphine oxide ligand
with bipolar structure was used to fabricate double-layer devices. The strong hole injection and transport ability of 1 was proved. The luminance of 414 cd m−2 was achieved with the device configuration ITO/Eu(TTA)3(CPPO)2(40 nm)/BCP (30 nm)/Mg:Ag (BCP = 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline), which is favorable among double-layer
organic light emitting devices based on small molecular Eu3+ complexes. The maximum current efficiency of 2.44 cd A−1 and external quantum efficiency of 1.55% demonstrate the potential application of 1 as a promising candidate for high-efficiency, simple-structure and pure red-emitting devices. 相似文献
9.
S. Vatnik M. C. Pujol J. J. Carvajal X. Mateos M. Aguiló F. Díaz V. Petrov 《Applied physics. B, Lasers and optics》2009,95(4):653-656
The three thermo-optic coefficients of the biaxial laser host KLu(WO4)2 are measured at 633 nm by a deflection method. Their values at 300 K amount to ∂
n
g
/∂
T=−7.4×10−6 K−1; ∂
n
m
/∂
T=−1.6×10−6 K−1 and ∂
n
p
/∂
T=−10.8×10−6 K−1. Nearly athermal propagation directions are found for polarizations along the N
m
and N
p
dielectric axes. 相似文献
10.
G. J. Kunde H. van Hecke K. Hessler C. Mironov 《The European Physical Journal C - Particles and Fields》2009,61(4):785-788
The Large Hadron Collider will allow studies of hard probes in nucleus-nucleus collisions which were not accessible at the
Relativistic Heavy Ion Collider—even the study of small cross-section Z
0-tagged jets becomes possible. Going beyond the measurement of back-to-back correlations of two strongly interacting particles
to measure plasma properties, we replace one side by an electromagnetic probe which propagates through the plasma undisturbed
and therefore provides a measurement of the energy of the initial hard scattering. We show that at sufficiently high transverse
momentum the Z
0-tagged jets originate predominately from the fragmentation of quarks and anti-quarks while gluon jets are suppressed. We
propose to use lepton-pair tagged jets to study medium-induced partonic energy loss and to measure in-medium parton fragmentation
functions to determine the opacity of the quark gluon plasma. 相似文献
11.
We report on the fabrication and characterization of planar and channel waveguides in KTiOPO4 crystals by 6.0 MeV C3+ ion implantation with the dose of 1×1014 ions/cm2. The dark mode spectroscopy of the planar waveguide was measured using a prism coupling arrangement. An increase of the both
n
x
and n
y
refractive indices induced by the annealing after implantation is believed to be responsible for waveguide formation. The
bright near-field intensity distribution of the transverse-electric and transverse-magnetic modes in the annealed channel
waveguide was collected and studied by end-coupling method. 相似文献
12.
P. Haro-González I. R. Martin F. Lahoz S. González-Pérez N. E. Capuj D. Jaque 《Applied Physics A: Materials Science & Processing》2008,93(4):977-981
Localized desvitrifiation in strontium barium niobate glass doped with Er3+ under laser irradiation has been carried out. The samples of this study have been fabricated by the melt quenching method
and doped with 5% mol of Er3+. A 1.5-W cw Ar laser was focused on the sample to obtain desvitrifiation of the glass. Evidence of the changes induced by
the Ar laser has been observed through the analysis of the photoluminescence of the Er3+ ions. The transitions corresponding to 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 have been studied to analyze structure changes. Microluminescence measurements have been carried out to spatially select
positions inside and outside the irradiated area. We have observed changes in the emission bands corresponding to these transitions.
The emission bands from Er3+ ions in the irradiated zone show a resolved structure while they are broadened outside that area. These changes in the optical
properties of the Er3+ ions indicate that the Ar-laser irradiation has produced a change in the local structure of the material. These results show
that a localized desvitrifiation has been produced after the laser action and the transition from glass to glass ceramic has
been completed. 相似文献
13.
O.?Caballero-Calero A.?García-Caba?es M.?Carrascosa F.?Agulló-López J.?Villarroel M.?Crespillo J.?Olivares 《Applied physics. B, Lasers and optics》2009,95(3):435-439
The generation of periodically poled structures in waveguides prepared by swift-heavy-ion (SHI) irradiation, i.e. in the electronic
stopping power regime, has been achieved following two different strategies. In one of them we have prepared bulk PPLN samples
by an applied electrical field, followed by irradiation with F ions at 22 MeV. After the ion irradiation, a waveguide showing
a high optical confinement is obtained, preserving the original PPLN structure. The second strategy consisted of electric
periodic poling of previously fabricated swift-ion-irradiated waveguides. To our knowledge this method has not been, so far,
successful for conventional implanted waveguides. The successful fabrication of PPLN structures on novel waveguides prepared
by SHI irradiation offers a promising potential for nonlinear integrated optical devices. 相似文献
14.
J.?Villarroel M.?Carrascosa A.?García-Caba?es O.?Caballero-Calero M.?Crespillo J.?Olivares 《Applied physics. B, Lasers and optics》2009,95(3):429-433
The photorefractive behaviour of a novel type of optical waveguides fabricated in LiNbO3 by swift heavy ion irradiation is investigated. First, the electro-optic coefficient r
33 of these guides that is crucial in the photorefractive effect is measured. Second, two complementary aspects of the photorefractive
response are studied: (i) recording and light-induced and dark erasure of holographic gratings; (ii) optical beam degradation
in single-beam configuration. The main photorefractive parameters, recording and erasing time constants, maximum refractive-index
change and optical damage thresholds are determined. 相似文献
15.
S. M. Kostritskii 《Applied physics. B, Lasers and optics》2009,95(3):421-428
Original results on investigation of the photorefractive effect in straight channels and integrated-optical circuits such
as a directional coupler, Y-splitter and Mach–Zehnder interferometer, exploiting titanium-indiffused and proton-exchanged
LiNbO3 waveguides, are presented. It has been found that the photorefractive damage is non-negligible for IR radiation with wavelengths
near 1.5 μm in all circuits studied. The new methods for accurate evaluation of small extents of photorefractive effect are
proposed. 相似文献
16.
M. Eichhorn 《Applied physics. B, Lasers and optics》2008,93(4):773-778
Using high-spatial and -spectral brightness laser diodes, a resonantly pumped high-power continuous-wave (CW) Er3+:YAG laser with up to 9 W of output power could be realized. Due to the lower upconversion loss in the 0.5% Er3+-doped crystal, intrinsic efficiencies of up to 64.3% and an optimum outcoupling of ∼20% were found. The output power was
compared to quasi-three-level theory with good agreement. In an optimized cavity design a mode fill efficiency of ∼95% was
achieved. 相似文献
17.
We report on monitoring of nitric oxide (NO) traces in human breath via infrared cavity leak-out spectroscopy. Using a CO
sideband laser near 5 μm wavelength and an optical cavity with two high-reflectivity mirrors (R=99.98%), the minimum detectable absorption is 2×10−10 cm−1 Hz1/2. This allows for spectroscopic analysis of rare NO isotopologues with unprecedented sensitivity. Application to simultaneous
online detection of 14NO and 15NO in breath samples collected in the nasal cavity is described for the first time. We achieved a noise-equivalent detection
limit of 7 parts per trillion for nasal 15NO (integration time: 70 s). 相似文献
18.
Al<Subscript>2</Subscript>O<Subscript>3</Subscript> plasma production during pulsed laser deposition
F. Caridi L. Torrisi A. M. Mezzasalma G. Mondio A. Borrielli 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(2):467-472
A Nd:YAG laser operating in second harmonic (532 nm), 3 ns pulse duration, 150 mJ pulse energy, and 10 Hz repetition rate,
is employed to irradiate Al2O3 target placed in high vacuum. The produced plasma is investigated by an ion collector used in time-of-flight configuration
and by a mass quadrupole spectrometer, in order to determine the equivalent plasma temperature and the atomic and molecular
composition. Pulsed laser deposition technique has been used to produce thin films on different substrates placed close to
the target. Different surface analyses, such as energy dispersive X-ray fluorescence (EDXRF), X-ray photoelectron spectroscopy
(XPS) and surface profilometry are employed to characterize the produced films. Measurements of ablation yield, plasma equivalent
temperature, acceleration voltage and characterization of grown thin films are presented and discussed. 相似文献
19.
N. A. Tolstik G. Huber V. V. Maltsev N. I. Leonyuk N. V. Kuleshov 《Applied physics. B, Lasers and optics》2008,92(4):567-571
Polarized excited state absorption spectra of Er, Yb:YAB are reported. The Stark levels of the 4I15/2, 4I13/2, and 4I11/2 multiplets of Er3+ have been derived from the measured low-temperature absorption and fluorescence spectra. The stimulated emission spectra
have been calculated using the reciprocity method, and the radiative lifetime of the erbium 4I13/2 level has been determined indicating high nonradiative decay rates. The thermal conductivity of Er-Yb-codoped YAB crystals
has been measured. 相似文献
20.
S. Rivier U. Griebner V. Petrov H. Zhang J. Li J. Wang J. Liu 《Applied physics. B, Lasers and optics》2008,93(4):753-757
Passive mode locking of the self-frequency doubling Yb:YAB crystal with a saturable absorber mirror is studied at the fundamental
wavelength. This laser has a very low threshold, and pulses as short as 85 and 87 fs are obtained for Ti:sapphire and diode
laser pumping, respectively. 相似文献