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861.
级联二阶非线性法布里-珀罗谐振腔特性分析 总被引:1,自引:0,他引:1
在小信号近似下,得出了级联二阶过程的表达式。利用该式的有效三阶极化率的表达式,讨论了存在二阶非线性光学晶体的法-珀谐振腔的非线性光学特性。分析表明,由于谐振腔的存在,通过非线性晶体的功率密度超过入射功率密度几十倍以上,因而产生较大的、随相位失配变化的非线性相位漂移。当相位失配接近2π时,获得基叔光的最大相位漂移。该最大相位漂移对应的相位失配随着入射功率密度、非线性晶体的地阶极化率和晶体长度而变化。 相似文献
862.
Ralph T. C. Huntington E. H. Harb C. C. Buchler B. C. Lam P. K. Mcclelland D. E. Bachor H.-A. 《Optical and Quantum Electronics》1999,31(5-7):583-598
We present unified theoretical expressions for laser intensity noise in the presence of injection locking and feedback. We discuss optimum control strategies for different configurations and frequency regions. We illustrate the various effects with experimental results from Nd : YAG non-planar ring oscillator lasers. 相似文献
863.
F. Bassani V. Lucarini 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,17(4):567-573
We use the Kubo response function formalism to derive the asymptotic behaviour of the harmonic generation susceptibilities
to all orders n. The results show a stringent correspondence with the ones previously obtained from the classical anharmonic oscillator model.
They are characterized by a dependence and a coefficient proportional to the trace of the (n+1)th derivative of the potential energy on the equilibrium density matrix. Using the above results we derive new Kramers-Kr?nig
relations and sum rules for all orders of harmonics susceptibilities.
Received 17 April 2000 相似文献
864.
M. Konôpka V. Bužek 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,10(2):285-293
We propose a method for entangling a system of two-level atoms in photonic crystals. The atoms are assumed to move in void
regions of a photonic crystal. The interaction between the atoms is mediated either via a defect mode or via a resonant dipole-dipole interaction. We show that these interactions can produce pure entangled atomic states. We analyze the problem with parameters typical
for currently existing photonic crystals and Rydberg atoms and we show that the atoms can emerge from photonic crystals in
entangled states. Depending on the linear dimensions of the crystal we estimate that a pair of atoms entangled in a photonic
crystal can be separated by tens of centimeters.
Receive 11 June 1999 and Received in final form 4 October 1999 相似文献
865.
It is useful to state propagation laws for a self-focusing laser beam or a soliton in group-theoretical form to be called
Lie-optical form for being able to predict self-focusing dynamics conveniently and amongst other things, the geometrical phase.
It is shown that the propagation of the gaussian laser beam is governed by a rotation group in a non-absorbing medium and
by the Lorentz group in an absorbing medium if the additional symmetry of paraxial propagation is imposed on the laser beam.
This latter symmetry, however, needs care in its implementation because the electromagnetic wave of the laser sees a different
refractive index profile than the laboratory observer in this approximation. It is explained how to estimate this non-Taylor
paraxial power series approximation. The group theoretical laws so-stated are used to predict the geometrical or Berry phase
of the laser beam by a technique developed by one of us elsewhere. The group-theoretical Lie-optic (or ABCD) laws are also
useful in predicting the laser behavior in a more complex optical arrangement like in a laser cavity etc. The nonlinear dynamical
consequences of these laws for long distance (or time) predictions are also dealt with. Ergodic dynamics of an ensemble of
laser beams on the torus during absorptionless self-focusing is discussed in this context. From the point of view of new physics
concepts, we introduce a stroboscopic invariant torus and a stroboscopic generating function in classical mechanics that is
useful for long-distance predictions of absorptionless self-focusing. 相似文献
866.
867.
868.
Michael C. Zerner Walter M. F. Fabian Renate Dworczak Dietmar W. Kieslinger Gert Kroner Hans Junek Max E. Lippitsch 《International journal of quantum chemistry》2000,79(4):253-266
The effect of conformation (E/Z isomerism), nature (donor/acceptor) of substituents, and endgroups (indandione, pyrazolone, pyrazoledione) on the molecular hyperpolarizability βvec of dicyanomethylene (hetero)aromatic dyes is investigated by means of semiempirical (AM1, ZINDO) molecular orbital calculations. Unless Z isomers are stabilized by intramolecular hydrogen bonding, generally E conformers have larger βvec's. Replacement of one nitrile group of the dicyanomethylene moiety by p‐aminoaryl rather than p‐R‐arylamino (R=NMe2, MeO, H, NO2) is found to be advantageous. Increasing the acceptor strength of 29 by successively replacing the carbonyl with dicyanovinyl groups leads to a maximum of βvec for the derivative with one rather than two C(CN)2 groups. With respect to endgroups, the indandione moiety generally is the least active group. Solvent effects are treated within the framework of the self‐consistent reaction field approximation. In most cases gas‐phase tendencies are either parallel or even reinforced if solvent effects are taken into account. The calculated results are compared with electric field induced second harmonic generation (EFISH) measurements. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 79: 253–266, 2000 相似文献
869.
The combined effects of hydrostatic pressure, presence and absence of hydrogenic donor impurity are investigated on the linear and nonlinear optical absorption coefficients and refractive index changes of a GaAs/Ga1−xAlxAs nanowire superlattice. The wave functions and corresponding eigenvalues are calculated using finite difference method in the framework of effective mass approximation. Analytical expressions for the linear and third order nonlinear optical absorption coefficients and refractive index changes are obtained by means of compact-density matrix formalism. The linear and third order nonlinear absorption coefficient and refractive index changes are presented as a function of photon energy for different values of hydrostatic pressure, incident photon intensity and relaxation time in the presence and absence of hydrogenic donor impurity. It is found that the linear and third order nonlinear absorption coefficients, refractive index changes and resonance energy are quite sensitive to the presence of impurity and applied hydrostatic pressure. Moreover, the saturation in optical spectrum and relaxation time can be adjusted by increasing pressure in presence of impurity whereas the effect of hydrostatic pressure is negligible in the case of absence of hydrogenic impurity. 相似文献
870.
M. Nakano S. Yamada H. Nagao K. Yamaguchi 《International journal of quantum chemistry》1999,71(4):295-306
In our previous study [Int. J. Quant. Chem., to appear], we have developed a novel numerical calculation scheme for a dynamics of quantum network for linear molecular aggregates under intense time‐dependent electric fields. In this approach, each molecule is assumed to be an electric dipole arranged linearly with an angle from the longitudinal axis, and the molecular interactions are taken into account by adding the radiations from these dipoles to the external electric fields. The effects of the radiations from all the dipoles involve the intermolecular distance, the speed of light, retarded polarization, and its first‐ and second‐order time derivatives at the position of each dipole. The quantum dynamics is performed by solving coupled Liouville equations composed of the Liouville equation for each dipole. In the present study, we develop a calculation approach of nonperturbative second hyperpolarizability γ in our novel approach and examine the γ of dimer models composed of two‐state molecules under the one‐photon near resonant intense laser fields. Similar phase transition‐like behavior in the field‐intensity dependence of the γ is observed. We also investigate the second hyperpolarizability spectra in the three‐photon resonant region for dimers composed of three‐state molecules, which mimic the electronic states of allyl cation. Contrary to the one‐photon resonant case, phase transition‐like behavior is not observed in the intensity dependence of γ in the three‐photon resonant region. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 71: 295–306, 1999 相似文献