共查询到20条相似文献,搜索用时 15 毫秒
1.
E.Ya. Glushko 《Optics Communications》2006,259(1):342-349
In this work, we consider the exact solution of the stationary cubic nonlinear equation in a semi-infinite nonlinear medium in contact with a one-dimensional photonic crystal. Two kinds of analytical solutions are found for an arbitrary magnitude of the nonlinearity: a standing-wave-like one containing the inverse elliptic function Eli(?∣m), and a one-wave-type solution for transmitted TE-polarized waves. An approximate two-wave solution is proposed to describe the field propagation through the nonlinear film covering the photonic crystal. It is shown that the problem of a mixed linear-nonlinear structure may be reduced to a transcendental kernel equation determining the field inside the nonlinear part of the medium. The light reflection from a Si/SiO2 layered structure in contact with an optically nonlinear medium is calculated. The angular-frequency photonic band diagram and power dependency are investigated. Local interface waveguide modes are considered. 相似文献
2.
The technique for determining the cell structural parameters of the confined one-dimensional photonic crystal, based on the
strict analytical representation of Floquet-Bloch waves in the form of inhomogeneous waves is proposed. 相似文献
3.
《Optik》2014,125(18):5041-5050
We established a general propagating model to investigate the spin Hall effect of light in one-dimensional photonic crystal. A polarized (spin dependent) Gaussian beam which was incident obliquely through one-dimensional photonic crystal was demonstrated. Having decomposed a polarized Gaussian beam into different plane wave components charactering individual wave vectors, we revealed the transmission coefficient and reflection coefficient of each plane wave which propagates through the one-dimensional photonic crystal. It enabled us to obtain exact solution to the electric field of transmitted and reflected beams, and the analytical formula of light intensity, accordingly. A method based upon the partial differentials with the intensity distribution of the transmitted and reflected Gaussian beams was presented to determine the transverse and longitude shifts explicitly. Spin dependent shifts in one-dimensional photonic crystal provide alternative evidence for the spin Hall effect of light. 相似文献
4.
S. G. Rautian 《Optics and Spectroscopy》2008,104(1):112-120
A one-dimensional harmonic model of a photonic crystal is considered using the methods of physical optics. The theoretical formalism is based on the notion of the Fresnel volume reflection and the system of two first-order differential equations, which are equivalent to the wave equation. Using the Rayleigh layer as an example, it is shown that the volume reflection plays a role of the friction, similar to the friction in oscillations of a pendulum, and, in a strongly inhomogeneous medium, can suppress field oscillations and turn the group velocity to zero. In the approximation of small modulation factor, the models of two, four, and six waves are considered. In the two-wave model, the dispersion relation contains a zone of inhomogeneous waves, whose width is determined by the Fresnel reflection coefficient from one period. The refinement in terms of the four-wave or six-wave model yields only a small correction to the position of the zone, retaining its width unchanged. The wavenumber as a function of frequency is described by a circle inside the zone of inhomogeneous waves and by a hyperbola outside this zone. Mathematically, the method used is significantly simpler than those based on the application of the Floquet theorem to the wave equation. It is shown that the notion of forbidden zones is inconsistent with respect to photonic crystals, and the term zones of inhomogeneous waves is proposed instead. 相似文献
5.
Enhanced noncollinear second harmonic generation in a finite one-dimensional photonic crystal is analyzed theoretically under conditions of pump field localization near the Bragg reflection. It is shown numerically that phase-matched second-harmonic generation can be implemented in a finite one-dimensional photonic crystal that does not satisfy the conventional phase-matching conditions calculated for effective Bloch modes with narrow spectral lines. The intensity of the generated second-harmonic signal exceeds the second-harmonic intensity attained under the conventional phase-matching conditions by more than an order of magnitude. This phenomenon is explained by interference between Bloch modes having similar amplitudes, wavenumbers, and spectral widths. Since the spatial spectra of waves propagating in a bounded medium have finite widths, the broadened spectral lines of proximate effective Bloch modes resulting from Bragg diffraction of waves tuned to the first transmission resonances near the photonic bandgap edge overlap, merging into a spectral profile with center shifted relative to the original effective Bloch wavevectors. This effect leads to modified phase matching conditions for second harmonic generation in a finite photonic crystal, which are written for the centers of the spectral profiles resulting from modal overlap, rather than for individual effective wavevectors. Substantially different phase matching conditions are obtained for weakly and strongly diffracted beams, whereas conventional phase matching conditions hold only for transmitted signals in the case of weak diffraction. 相似文献
6.
Directed modes and leaky modes in a confined one-dimensional photonic crystal are analytically described. The dispersion relation
of these modes is written as the transverse resonance condition of Floquet-Bloch waves, taking into account phase shifts at
interfaces with adjacent media. 相似文献
7.
Phase modulation methods for surface electromagnetic waves propagating at the interface between a homogeneous medium and a one-dimensional photonic crystal have been analyzed numerically and theoretically. Modulation is performed by changing the geometrical parameters of the microrelief on the surface of the photonic crystal. The phase modulation methods under consideration can be used to create optical elements for surface waves, in particular, lenses, prisms, and diffraction gratings. A Bragg grating has been calculated as an example. According to the simulation results, the average coefficient of reflection of a surface wave in the band gap is 0.95. 相似文献
8.
The dispersion characteristics of a one-dimensional photonic crystal are analyzed in detail on the basis of the exactly solvable Kronig-Penney model for the particular case of a periodic system consisting of an infinite number of insulator-air layers arranged in the direction of propagation of radiation. An analytical solution is obtained, and the behavior of eigenwaves near the edges of the photonic band is thoroughly studied. The behavior of roots on a complex plane is qualitatively analyzed with the use of approximate dispersion characteristics obtained via expanding the solution of the wave equation in series in terms of the harmonics of the lattice spacing. It is shown that, despite the amplifying properties of the material, no gain in the photonic band gap is present, because of the interference quenching of waves. 相似文献
9.
Tsuyoshi Ueta 《Applied Physics A: Materials Science & Processing》2014,116(3):863-871
The lattice-vibrating metal photonic crystal is exactly a system of dynamical Casimir effect connected in series, and so we can expect that a dynamical Casimir effect is enhanced by the photonic band effect. In the present study, when an electromagnetic field between metal plates is in the ground state in a one-dimensional metal photonic crystal, the radiation of electromagnetic wave in excited states has been investigated by artificially introducing lattice vibration to the photonic crystal. In this case as well as a dynamical Casimir effect, it has been shown that the harmonics of a ground state are generated just by vibrating a photonic crystal even without an incident wave. The dependencies of the radiating power on the number of layers and on the wavenumber of the lattice vibration are remarkable. It has been found that the radiation amplitude on lower excited states is not necessarily large and radiation on specific excited levels is large. 相似文献
10.
11.
The excitation of well-localized oblique surface waves above the surface of a dielectric with a one-dimensional array of perfectly
conducting wires is studied theoretically using the attenuated total internal reflection method. It is assumed that the distance
between the wires and their diameter are much smaller than the surface wavelength. The frequencies of excited surface waves
are much lower than the plasma frequency of the metal, and their electric field is orthogonal to the wires. It is shown that
such surface waves can be excited with the help of a homogeneous TM wave as well as with the help of a homogeneous wave with
an electric field polarized perpendicularly to the wires. It is found that in the course of excitation of oblique waves, the
incident TM wave is partly polarized into a wave of the TE type. 相似文献
12.
M. Yu. Barabanenkov A. F. Vyatkin 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(5):931-937
The scattering of transmitted and evanescent electromagnetic waves by threadlike photonic crystals, made of different materials, is studied theoretically. The reflection and transmission spectra of the waves, the electric vector of which is parallel to the threads, are calculated on the basis of a matrix Riccati equation. The physical reasons for the appearance of transparency peaks in the transmission spectra of threadlike photonic crystals are discussed. It is established that narrowband filters suggested previously and formed by a periodic system of Si threads about 1 μm in diameter and adjusted to a wavelength of 1.5 μm totally lose their filtering capabilities at small deviations (about 5%) from the thread diameter. However, the reflection and transmission spectra of filters containing periodically packed metallized Si threads are stable in the case of such variations in thread size. It is shown that threadlike crystals are an effective discrete mirror for radiation of the near- and mid-IR spectral range. The capabilities of threadlike crystals for filtering homogeneous and inhomogeneous waves are shown. 相似文献
13.
A. A. Greshnov M. A. Kaliteevskiĭ R. A. Abram S. Brand G. G. Zegrya 《Physics of the Solid State》2007,49(10):1999-2003
An analytic theory of the density of states in one-dimensional disordered photonic crystals is proposed. It is shown that the problem of the density of optical modes can be reduced in the small dielectric contrast approximation to solving a generalized Fokker-Planck equation for the distribution function of the logarithmic derivative of the electric field (the wave phase). The exact analytic solution and density-of-states asymptotics deep in the band gap of the photonic crystal and close to the band gap edge are derived. The results obtained agree well with the empirical relations derived earlier from numerical experiments. 相似文献
14.
S. Ya. Vetrov R. G. Bikbaev I. V. Timofeev 《Journal of Experimental and Theoretical Physics》2013,117(6):988-998
Optical Tamm states localized at the edges of a photonic crystal bounded from one or both sides by a nanocomposite have been studied. The nanocomposite consists of metallic nanoinclusions, which have a spherical or orientationally ordered spheroidal shape and are dispersed in a transparent matrix, and is characterized by the resonant effective permittivity. The transmission, reflection, and absorption spectra have been calculated for waves with longitudinal and transverse polarizations in such structures at the normal incidence of light. The spectral manifestation of Tamm states that is due to the existence of negative values of the real part of the effective permittivity has been analyzed for the visible spectral range. It has been established that the characteristics of Tamm states localized at the edge of the photonic crystal depend strongly both on the concentration of nanoballs in the nanocomposite film and on its thickness. Modes formed by two coupled Tamm plasmon polaritons localized at the edges of the photonic crystal adjacent to two nanocomposite layers have been examined. It has been shown that, in the case of the anisotropic nanocomposite layer adjacent to the photonic crystal, each of two orthogonal polarizations of the incident wave corresponds to a specific frequency of the Tamm state localized at the edge; owing to this property, the transmission spectra of such a structure are polarization sensitive. 相似文献
15.
The interaction of the electromagnetic radiation with one-dimensional photonic crystal consisting of metal and transparent dielectric medium is studied numerically. Dielectric permeabilities of the electron plasma in the metal are considered both in the quantum Mermin and in the classical Drude–Lorentz approaches. It is shown that the reflection, transmission and absorption-frequency zones of electromagnetic radiation appear in the photonic crystal. In addition, the reflectance, transmittance and absorptance optical coefficients for such photonic crystal in the quantum approach differ from those coefficients in the Drude–Lorentz approach. 相似文献
16.
《Waves in Random and Complex Media》2013,23(2):152-168
Mathematical formulation for analysis of electromagnetic wave scattering from multilayer anisotropic homogeneous metamaterial structures with general tensors is presented. The result is reflection and transmission matrices formulas. Then, closed form formulas are extracted for structures with diagonal tensors. We try to find structures with exact zero reflection for general incident waves. New cases with zero and low reflection are introduced. 相似文献
17.
It is shown that both TE and TM waves incident on the surface of a semi-infinite one-dimensional thin-layer gyrotropic magnetic
photonic crystal of the magnetic-nonmagnetic dielectric type can experience a number of refraction anomalies in an external
electric field due to the effect of hybridization of evanescent waves in magnetic and nonmagnetic layers. These anomalies
are absent under the same conditions in spatially homogeneous media consisting of the same materials as the photonic crystal. 相似文献
18.
19.
Highly efficient transmission of 1.5-microm light in a two-dimensional (2D) photonic crystal slab waveguide is experimentally demonstrated. Light waves are shown to be guided along a triple-line defect formed within a 2D crystal and vertically by a strong index-guiding mechanism. At certain wavelength ranges, complete transmission is observed, suggesting lossless guiding along this photonic one-dimensional conduction channel. 相似文献
20.
We calculate the Sommerfeld precursor that results after transmission of a generic electromagnetic plane wave pulse with transverse electric polarization, through a one-dimensional rectangular N-layer photonic crystal with two slabs per layer. The shape of this precursor equals the shape of the precursor that would result from transmission through a homogeneous medium. However, amplitude and period of the precursor are now influenced by the spatial average of the plasma frequency squared instead of the plasma frequency squared for the homogeneous case. 相似文献