共查询到20条相似文献,搜索用时 31 毫秒
1.
Yoav Linzon Boris A. Malomed Michael Zaezjev Roberto Morandotti Maite Volatier Vincent Aimez Richard Ares Shimshon Bar-Ad 《Central European Journal of Physics》2008,6(3):555-562
We study nonlinear interactions between discrete optical solitons that propagate in different regimes of diffraction, and
the nonlinear scattering of dispersive waves by local optical potentials. It is well known in optics that when linear coherent
waves meet, they interfere without interactions. Linear waves also scatter through local optical structures not exchanging
any power with the guided modes of these structures. As a focusing Kerr nonlinearity is present, such linearly-inhibited phenomena
can exist. Our studies are performed in silica and AlGaAs nonlinear waveguides, excited by ultra-short pulses in the near
infrared.
Presented at 9-th International Workshop on Nonlinear Optics Applications, NOA 2007, May 17–20, 2007, Świnoujście, Poland 相似文献
2.
Ulf Peschel Christoph Bersch Georgy Onishchukov 《Central European Journal of Physics》2008,6(3):619-627
In this paper we discuss the joint propagation of a periodically modulated field and a pulse of different frequency in an
optical fiber. The pulse experiences the action of an index lattice induced via cross-phase modulation by the periodic field.
We predict effects of discreteness to show up both in the temporal and in the spatial domain. For large walk-off between the
two fields one should observe Bloch oscillations in frequency space, where discrete diffraction is expected to occur for equal
velocities of both waves.
Presented at 9-th International Workshop on Nonlinear Optics Applications, NOA 2007, May 17–20, 2007, Świnoujscie, Poland 相似文献
3.
A. V. Khomich N. A. Poklonskii N. M. Lapchuk R. A. Khmel’nitskii V. A. Dravin S. Munkhtsetseg 《Journal of Applied Spectroscopy》2007,74(4):537-543
We used IR spectroscopy and electron spin resonance (ESR) to investigate defect reconstruction processes occurring in diamond
crystals due to their implantation with H+ ions with energies of 65–350 keV and subsequent isochronous annealing in the temperature range 250–1550°C. We found that
most of the hydrogen in diamonds implanted with protons is in an IR-inactive state. Magnetic hysteresis related to radiation
defects in diamond is observed for the first time at room temperature using ESR.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 485–490, July–August, 2007. 相似文献
4.
V. A. Svetlichnyi M. P. Samtsov O. K. Bazyl’ O. V. Smirnov D. G. Mel’nikov A. P. Lugovskii 《Journal of Applied Spectroscopy》2007,74(4):524-532
We present results of experimental and theoretical studies of the optical characteristics of a new indotricarbocyanine dye
that is capable of effectively limiting the power of laser radiation in the visible spectral range. The spectral-luminescent
and energy characteristics of the dye molecules and their absorption spectra from the excited state with nanosecond resolution
are investigated experimentally. Quantum-chemical methods are used to calculate electronic absorption spectra from the ground
(S0 → Sn) and excited (S1 → Sn) states and to determine the nature of electronic states of the molecule and the rate constants of intramolecular photophysical
processes. The results of the theoretical research agree with experimental data. It is shown that the investigated dye has
singlet-singlet absorption at 400–600 nm. Nonlinear absorption of the dye upon excitation by radiation of the second harmonic
of a Nd:YAG laser is studied by z-scanning with an open diaphragm. The ratio of dye absorption cross sections from the excited
and ground states at 532 nm is determined in the framework of a three-level model. The results are compared with those for
previously studied compounds.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 473–480, July–August, 2007. 相似文献
5.
Andrzej W. Domanski Rafal Cieslak Miroslaw A. Karpierz Daniel Budaszewski Tomasz R. Wolinski 《Central European Journal of Physics》2008,6(3):628-633
This paper analyzes the second harmonic generation (SHG) efficiency of light with partial temporal coherence due to depolarization
effects in birefringent media. It discusses relations between SHG efficiency fading, light source spectrum, crystal birefringence,
and phase matching conditions. The efficiency of SHG pumped by the partially coherent light beam that may depolarize light
in nonlinear birefringent crystal is also analyzed. The basic theory of SHG with its modification for partially coherent light
with depolarization and some numerical calculations of the SHG process are described.
Presented at 9-th International Workshop on Nonlinear Optics Applications, NOA 207, May 17–20, 2007, Świnoujście, Poland 相似文献
6.
7.
We present a review of results from study of the nonlinear optical properties and relaxation processes in lead chalcogenide
quantum dots embedded in glass matrices of various compositions, and also designs for bleachable media based on these materials
for Q-switched and mode-locked solid-state lasers in the near IR range. We consider the conditions which should be satisfied
by the spectroscopic characteristics of saturable absorbers for realization of passive Q-switching and mode-locking in solid-state
lasers.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 701–725, November–December, 2007. 相似文献
8.
I. A. Denisov A. G. Selivanov K. V. Yumashev A. V. Anan’ev L. V. Maksimov N. V. Ovcharenko V. N. Bogdanov A. A. Lipovskii A. N. Vlasova 《Journal of Applied Spectroscopy》2007,74(6):866-871
We have studied the nonlinearity of the refractive index at a wavelength of 1.08 μm for optical lead silicate and lead phosphate
tellurite glasses of different compositions. We have shown that the nonlinear refractive index n2 increases as the lead content increases in lead silicate glasses and as the tellurium content increases in lead phosphate
tellurite glasses, where the latter are typically have higher values of n2, as high as 24·10−13 cgs units (47·10−16 cm2/W), and lower Rayleigh losses. We have established a correlation between the nonlinear refractive index and the microstructure
of the studied glasses. The highly nonlinear glasses are distinguished by extensive fluctuations in the heavy metal oxide
concentration which are “frozen” during cooling of the glass melt.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 780–784, November–December, 2007. 相似文献
9.
We have used x-ray photoelectron spectroscopy to investigate the charge state of oxygen found in the basal structural plane
of YBa2Cu3O6+γ.. We have observed a change in this state after thermal treatment, with a transition to the adjacent structural phase region.
We have shown that changes in the charge state of oxygen can be used as an indicator of structural changes occurring in YBa2Cu3O6+δ.. We have found that the rate of structural relaxation yttrium barium cuprate depends on the amount of structural water
it contains.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 195–198, March–April, 2007. 相似文献
10.
Satish D Joglekar 《Pramana》1988,31(6):461-467
We discuss renormalization of an O(3) gauge model with the gauge fixing term given by ℒg.f.=-1/ζ|(∂μ-igA
3
μ
)W
+μ|2-(1/2α)(∂A
3)2. We utilize earlier results on the general theory of renormalization of gauge theories in quadratic gauges to prove multiplicative
renormalizability of the theory together with a subtractive renormalization of gauge fixing and ghost terms. We show that
this model has a double BRS invariance and that it is preserved under renormalization. 相似文献
11.
We examine the entropy of stationary nonequilibrium measures of boundary driven symmetric simple exclusion processes. In contrast
with the Gibbs–Shannon entropy (Bahadoran in J. Stat. Phys. 126(4–5):1069–1082, 2007; Derrida et al. in J. Stat. Phys. 126(4–5):1083–1108, 2007), the entropy of nonequilibrium stationary states differs from the entropy of local equilibrium states. 相似文献
12.
We vindicate our results in Mars and Senovilla (Phys Rev D 54, 6166–6180, 1996), which have been recently put in doubt or
misunderstood in García and Ulloa (Gen Rel Grav 39, 1639–1650, 2007). In particular, we maintain that there indeed exist axially
symmetric differentially rotating perfect-fluid solutions satisfying all energy conditions within the family of solutions
presented in Senovilla (Class Quant Grav 9, L167–L169, 1992). We remark that the existence of an axis of symmetry can never
be “re-interpreted” as the existence of a Killing horizon, and vice versa. We prove that such horizons are simply impossible
for the perfect fluids within the family, and that regular axes of symmetry (or curvature singularities) are the only possibilities.
Other inaccuracies or misunderstandings appeared in García and Ulloa (Gen Rel Grav 39, 1639–1650, 2007) are clarified. 相似文献
13.
W. Huang R. Richert 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,66(2):217-221
We investigate the nonlinear dielectric effects in a polar viscous liquid, propylene carbonate, by analyzing the voltage and
current traces obtained for a sinusoidal electric field at a frequency of 1 kHz and field amplitudes as high as 162 kV/cm.
The main source of non-linear behavior results from the energy absorbed from the field and is understood quantitatively. However,
there is a qualitative difference in the behavior of the field induced change, Δε′′(E), and the third harmonic amplitude of the current, I3ω. Although both Δε′′(E) and I3ω are considered reliable measures of non-linear behavior, we show here that the third harmonic signal reflects only those
non-linear responses that are instantaneous on the time scale of the test frequency. 相似文献
14.
In this paper we investigate the Schwinger parametric representation for the Feynman amplitudes of the recently discovered
renormalizable quantum field theory on the Moyal non commutative space. This representation involves new hyperbolic polynomials which are the non-commutative analogs of the usual “Kirchoff” or “Symanzik” polynomials of commutative field
theory, but contain richer topological information.
Work supported by ANR grant NT05-3-43374 “GenoPhy”. 相似文献
15.
Satish D Joglekar 《Pramana》1989,32(3):195-207
We discuss the general theory of renormalization of unbroken gauge theories in the nonlinear gauges in which the gauge-fixing
term is of the form
We show that higher loop renormalization modifiesfα [A] to contain ghost terms of the form
and show how the corresponding ghost terms are deduced fromfα [A, c, c] uniquely. We show that the theory can be renormalized while preserving a modified form of BRS invariance by multiplicative
and independent renormalizations onA, c, g, η, ζ, τ. We briefly discuss the independence of the renormalized S-matrix from η,ζ, τ. 相似文献
16.
A. Orefice 《Il Nuovo Cimento D》1986,8(3):318-332
Summary The relativistic quasi-linear theory of electron cyclotron fluctuations is developed for a homogeneous plasma. Expressions
are given for the absorption and emission coefficients, consistently with the currently employed linear theory. The extension
to the inhomogeneousplasma case is considered and shown to allow the analysis of wave propagation, absorption and emission
in plasmas of physical interest.
Riassunto Si sviluppa la teoria quasi lineare relativistica per le fluttuazioni di onde elettroniche di ciclotrone per un plasma omogeneo. Si otteggono inoltre le espressioni dei coefficienti d'assorbimento ed emissione del plasma, consistentemente con la teoria lineare correntemente usata. Si considera infine l'estensione della teoria ad un plasma disomogeneo, applicandola all'analisi quantitativa di propagazione, assorbimento ed emissione di onde di ciclotrone.
Резюме Для однородной плазмы развивается релятивистская квазилинейная теория электронных циклотронных флуктуаций. Приводятся вйражения для коэффициентов поглощения и испускания, соответствующих повсеместно используемой линейной теории. Рассматривается обобщения и излучения волн в плазме в физическн интересных случаях.相似文献
17.
18.
P. F. Yu J. G. Cai J. M. Liu G. T. Shen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(1):151-158
We investigate the phase decoherence effects on
the entanglement of a two-qubit anisotropic Heisenberg
model
with a nonuniform magnetic field in the x–z-plane. As a
measure of the entanglement, the concurrence of the system is
calculated. It is shown that when the magnetic field is along the
z-axis, the nonuniform and uniform components of the field have
no influence on the entanglement for the cases of
and
, respectively. But when
the magnetic field is not along the z-axis, both the uniform and
the nonuniform components of the field will introduce the
decoherence effects. It is found that the effects of the
Heisenberg chain's anisotropy in the Z-direction on the
entanglement are dependent on the direction of the field.
Moreover, the larger the initial concurrence is, the higher value
it will exhibit during the time evolution of the system for a
proper set of the parameters ν, Δ, θ, γ
, B and b. 相似文献
19.
Max Jammer 《Physics in Perspective (PIP)》2007,9(3):266-280
I summarize the historical development of concepts of time in physics from antiquity to the end of the twentieth century.
Editors’ Note: Max Jammer received the American Physical Society/American Institute of Physics Abraham Pais Prize for the
History of Physics for 2007, “For his groundbreaking historical studies of fundamental concepts in physics, including his
comprehensive account of the development of quantum mechanics.” We publish here his Pais Prize Lecture, which was presented
at the APS meeting in Jacksonville, Florida, on April 16, 2007. 相似文献
20.
A. P. Zazhogin A. A. Zazhogin A. I. Komyak D. S. Umreiko 《Journal of Applied Spectroscopy》2007,74(5):622-625
We have studied the effect of irradiation on the uranyl nitrate — acetone and uranyl perchlorate — acetone systems. We have
established that when the uranyl perchlorate — acetone system is irradiated, polymerization of the acetone occurs and the
catalyst for the process is excited uranyl complexes. In the polymer, uranium is found in the form of nanoclusters of pentavalent
and tetravalent uranium, formed as a result of photochemical reactions. Polymerization does not occur in the uranyl nitrate
— acetone system. We consider possible factors responsible for the noted differences.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 565–568, September–October, 2007. 相似文献