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设计了一种缺陷模迁移光子晶体微腔全光开关. 两条二维三角晶格空气孔光子晶体波导由一个光子晶体微腔连接, 在微腔的点缺陷中填充掺有少量偶氮聚合物的苯乙炔类液晶. 通过调节控制光的偏振态, 使偶氮聚合物发生顺-反异构化反应, 带动液晶分子重新取向, 从而改变光子晶体微腔的谐振波长, 进而实现光的通过与截止. 运用时域有限差分法和平面波展开法分析 了二维光控液晶光子晶体微腔全光开关的光学特性. 数值计算结果表明: 对于1.55 μ通信波段通过外界偏振光控制所填充的向列相液晶 的折射率可以实现对光波的导通与截止. 分析结果显示, 此开关具有阈值低, 消光比较大, 体积小等优点.
关键词:
二维光子晶体微腔
波导
时域有限差分(FDTD)
液晶 相似文献
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将二维三角晶格光子晶体波导和微腔结构结合,优化设计了一种二维三角晶格光子晶体共振耦合腔波导,运用时域有限差分法(FDTD)模拟共振耦合腔波导TE偏振光的透射谱,通过透射谱得到传输光的透射率和群速度。结果表明,合适参数的二维三角晶格共振耦合腔波导在波长1.551μm处的群速度为c/130、透射率为20.1%,在波长1.502μm处的群速度为c/50、透射率为29.2%。运用平面波展开法(PWE)计算的该波导的能带结构对慢光特性进行了分析。这种慢光特性的光子晶体波导将在光存储、光延迟及光子集成等方面有潜在的应用价值。 相似文献
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液晶调制光子晶体微腔光衰减器 总被引:4,自引:1,他引:3
设计了一种二维液晶调制光子晶体微腔光衰减器。两条二维三角晶格空气孔光子晶体波导由一个光子晶体微腔连接,在微腔的点缺陷中填充苯乙炔类液晶。通过施加不同电压,电场诱导液晶取向以改变液晶的折射率,从而改变光子晶体微腔的谐振波长,进而实现光传播强度调节。运用时域有限差分方法和平面波展开法分析了二维液晶调制光子晶体微腔光衰减器的光学特性。数值计算结果表明:对于1.55μm通信波段,通过外界电场控制所填充的向列相液晶的方向可以对这种二维液晶调制光子晶体微腔光衰减器实现3.40%~99.58%的可调谐光输出。 相似文献
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以二维三角晶格光子晶体为研究对象,在该光子晶体中引入两行以一行耦合介质柱为间距的平行单模线缺陷波导.通过分析和研究光子晶体波导耦合结构的耦合和解耦合特性,发现在不同频率下耦合波导的耦合长度不同.利用平面波展开法和定向耦合原理计算了在不同入射光频率下,缺陷波导间耦合波导的耦合长度,设计了一种新型超微光子晶体波导耦合型三波长功分器,实现了归一化频率分别为0.369、0.394、0.435的光波的分束效果.采用时域有限差分法验证了该功分器具有很好的功率分配效果.本文结果有助于光子晶体新型滤波器、定向耦合器、波分复用器、偏振光分束器以及光开关等光子器件的研究. 相似文献
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基于光子晶体异质结构实现光波单向传输在全光网络和光信息处理中有重要意义。基于全反射原理设计了两种由二氧化硅和锗材料构筑的三角晶格光子晶体波导异质结构,运用时域有限差分法对该结构在宽频带内的单向传输特性进行分析。通过改变正向出射端波导宽度对结构进一步优化,实现了在异质结构一中,TE模式光波在1458~1517nm波长范围内正向透射率高于0.8,透射对比度高于0.9的单向传输;在异质结构二中,TM模式光波在1498~1689nm波长范围内正向透射率高于0.8,透射对比度接近于1的单向传输。 相似文献
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基于平面波展开法,设计了二维正方晶格和三角晶格光子晶体缺陷结构,数值模拟了TE模、TM模式的光子晶体禁带特性,计算了二维三角晶格光子晶体缺陷结构的模式分布。结果表明,光子晶体缺陷结构能够形成很好的禁带特性和模式结构,研究结论为光子晶体波导器件的开发提供参考。 相似文献
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Jun-ichiro Sugisaka Noritsugu Yamamoto Kazuhiro Komori Masahide Itoh 《Optics Communications》2008,281(23):5788-5792
A two-dimensional photonic crystal waveguide with a novel geometry is introduced. The center line of this waveguide is bent along a free-curve such that the direction of the propagating light can be changed without scattering or reflection losses. The design method is described for a triangular lattice, its optical properties such as transmission spectrum and dispersion relation are calculated, and actual devices are then fabricated and demonstrated that they worked as optical waveguides. 相似文献
12.
Optimal tunability of waveguides based on silicon photonic crystals infiltrated with liquid crystals
J. Cos J. Ferré-Borrull J. Pallarès L. F. Marsal 《Optical and Quantum Electronics》2011,42(8):487-497
In this work we study the optimization of the tunability range in waveguides based on two-dimensional silicon photonic crystal
infiltrated with liquid crystal. The analyzed structure consists of a two-dimensional silicon photonic crystal with a triangular
lattice of circular holes where a line of scatterers in the direction Γ–K has been replaced by a line of circular holes with
different radius infiltrated by E7 liquid crystal. To this end, we use the plane-wave expansion method considering anisotropy
and modelling supercells to account for the lattice defects that define the waveguide. Finally we study the field distributions
of the guided modes in order to analyze their symmetries and confinement. 相似文献
13.
Lü ShuYuan ZHAO JianLin & ZHANG Dong Institute of Optical Information Science Technology Shanxi Key Laboratory of Optical Information Technology School of Science Northwestern Polytechnical University Xi’an China 《中国科学:物理学 力学 天文学(英文版)》2010,(3)
The slow light propagation in a line waveguide in the two-dimensional triangular photonic crystal has been numerically studied, based on which a wideband photonic crystal waveguide with low group-velocity and low dispersion is proposed. The numerical simulation analysis shows that it is possible to maximize the group index and minimize the group-velocity dispersion in wide bandwidth by increasing the radius of the basic air hole and changing the position of the first two rows of air holes in photonic crysta... 相似文献
14.
We have studied the coupling of a classic ridge waveguide with a two-dimensional photonic crystal (PC) waveguide, using finite-difference time-domain calculations. The ridge waveguide exhibits only a weak refractive-index confinement of light, as it is commonly used in buried-heterostructure or ridge-waveguide lasers. The light is coupled to a PC waveguide that consists of one missing row along the ?K direction in a triangular lattice of air cylinders in AlGaAs. We compare various designs for PC tapers with that of a classic taper and for butt coupling. The calculation yields high coupling efficiency that exceeds 80% for a 2.5-microm-long PC taper. In addition, the dependence of the efficiency on the PC air-fill factor and on alignment tolerances is analyzed. 相似文献
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《Photonics and Nanostructures》2009,7(1):12-18
Calculations of angular-dependent reflectance and polarimetry spectra of nanoporous anodic alumina-based two-dimensional photonic crystal slabs are presented. The calculations are obtained using a scattering matrix numerical model that gives the polarization change as a function of the incidence angle and of the wavelength. The results reveal that the incident light can couple to several modes propagating in the photonic crystal slab at different angles with respect to the sample surface, and that the number of these modes increases with increasing pore depth. Two different lattice structures are studied: triangular and square. For the triangular lattice the off-diagonal components of the Jones Matrix show a certain amount of cross-polarization, while for the square lattice, there is no cross-polarization. 相似文献
17.
The spatial distribution of the electromagnetic field in a two-dimensional photonic crystal with a lattice defect is investigated.
It is shown that in such a structure the field can be localized in a region smaller than one wavelength in size. The dependence
of the spectrum of defect modes on the parameters of a two-dimensional photonic crystal is investigated. The light field at
the exit of the photonic crystal possesses properties of a nonradiative mode, making it possible to achieve spatial resolution
in the near-field much higher than the radiation wavelength. The possibilities of using this phenomenon in optical near-field
microscopy to produce optical memory devices and to increase the efficiency of nonlinear optical interactions are discussed.
Pis’ma Zh. éksp. Teor. Fiz. 70, No. 5, 323–328 (10 September 1999) 相似文献
18.
《Physics letters. A》2006,359(6):723-727
Optical limitation in a 2D nonlinear photonic crystal (NPC) has been studied in this Letter. Since the optical limitation is due to Bragg scattering induced by the variation of nonlinear refractive index, it is sure that the optical limitation can be realized in nonlinear photonic crystal. The light propagation characteristics in a two-dimensional nonlinear photonic crystal with triangular lattice has been calculated by using the finite-difference time-domain algorithm, which is constructed by placing certain number of nonlinear dielectric rods in a linear photonic crystal. The optical limiting effects at 1.300 and 0.504 μm have been obviously obtained for TE polarization and TM polarization, respectively. 相似文献
19.
S. G. Romanov 《Physics of the Solid State》2017,59(7):1356-1367
The structure and optical diffraction properties of monolayers of monodisperse spheres crystallized on transparent dielectric substrates are studied. Two types of diffraction phenomena are considered: surface light diffraction on the lattice of spheres and waveguide resonances in the monolayer plane. For experimental study of these phenomena, optical retroreflection and transmission spectra are measured as functions of the light incidence angle and azimuthal orientation of the incidence plane. The monolayer structures determined by scanning electron microscopy and light diffraction methods are in quantitative agreement. It is concluded that one-dimensional Fraunhofer diffraction is applicable to describe surface diffraction in the hexagonal lattice of spheres. In the case of oblique light incidence, anisotropy of diffraction and transmission spectra depending on the light incidence plane orientation with respect to the sphere lattice and linear polarization of incident light is detected. Waveguide resonances of the planar two-dimensional photonic crystal are approximated within the light diffraction model in the “empty” hexagonal lattice. The best approximation of the waveguide resonance dispersion is achieved using the effective refractive index, depending on the wavelength. Surface diffraction suppression by waveguide resonances of the photonic crystal is demonstrated. Surface diffraction orders are identified as diffraction at singular points of the Brillouin zone of the planar twodimensional photonic crystal. 相似文献