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为了消除光子晶体环形腔滤波器的多模特性,通过在环形腔的输出负载通道中引入点缺陷,提出了一种复合缺陷光子晶体滤波器结构。将线缺陷作为主波导,将环形腔和点缺陷相结合作为负载波导来实现对特定波长的滤波。分析了光子晶体整体介质柱折射率、点缺陷的折射率以及点缺陷的尺寸对滤波器滤波特性的影响。令m=r-point/r,由数值模拟分析得出,当m取0~0.6时,B端口输出的滤波波长值没有发生改变,而在m∈[0.6,1.8]的合理区间范围内,若改变点缺陷介质柱半径,则可实现滤波器的单纵模滤波和滤波特性的可调谐,这将对多通道滤波器结构的设计提供有效的理论参考。 相似文献
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提出一种基于光子晶体环形腔的四波长THz滤波器,该滤波器在光子晶体结构中引入两个环形腔,且环形腔内部各增加一个正方形介质柱,四周各引入一个散射介质柱。应用基于时域有限差分法(FDTD)的Rsoft软件进行仿真分析,结果表明通过对内部正方形介质柱的边长、散射介质柱半径以及耦合介质柱半径等结构参数的调节,可以滤出74.813,76.98,78.168和78.883 m四个太赫兹波长。该滤波器性能优良,透过率高、Q值高、信道隔离度大,对于THz技术应用具有重要意义。 相似文献
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在光子晶体环形腔中增加两个散射介质柱,构成一个新型的环形腔滤波器,该滤波器能有效选择光波透过,光波的透射率可以达到90%以上,带宽较小.可通过这两种不同的调节方式使滤波器中波长的带宽和数值进行任意的改变:1)减小散射介质柱半径,从负载波导输出波长的带宽变大,主波导中波长的带宽减小;增大其半径时,它们的变化正好相反.2)改变耦合区域介质柱半径的大小,滤波器中波长的数值也会相应地变化,它与介质柱半径的变化呈正比,并且透射率也会发生明显的变化.这就为其在制备集成光子器件的应用中奠定了基础.
关键词:
环形腔
滤波器
散射介质柱
透射率 相似文献
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提出一种在光子晶体十字波导中加入点阵缺陷的特殊结构波导.采用时域有限差分法(FDTD)对该结构的导波特性进行数值模拟,计算结果表明:含缺陷结构的光子晶体波导的透射光谱较不含缺陷结构光子晶体波导的透射光谱带宽变得更窄,此结构具有窄带滤波作用.当改变波导中缺陷结构折射率取值时,该波导透射光的中心频率随缺陷介质折射率的增大而线性减小.改变中心缺陷介质柱直径时,该波导透射光波中心频率随介质柱直径的增大也呈逐渐减小趋势.这种光子晶体十字波导可作为一种窄带滤波器、分光器和可调式选频器等器件,具有一定的应用前景. 相似文献
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光子晶体异质结耦合波导光开关 总被引:2,自引:0,他引:2
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平行的单模线缺陷波导,以一行耦合介质柱为间距,通过调节部分耦合介质柱的折射率,构筑了光子晶体异质结耦合波导光开关结构。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,缺陷波导间耦合介质柱的折射率不同时的耦合长度,确定了合适的光子晶体异质结耦合波导光开关的结构参数。利用时域有限差分法研究了该光开关中耦合介质柱的折射率变化及异质结构介质柱的位置分布对光信号输出路径的影响。结果表明,通过改变该结构中耦合介质柱的折射率可以改变光的输出路径,可实现光的开关行为。并且异质结构介质柱位置的随机分布对该光开关的影响不大,有助于光子晶体新型滤波器、定向耦合器、波分复用器以及光开关等光子器件的研究。 相似文献
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等离子体填充到一维介质-真空微波光子晶体的缺陷层构成一种可调谐单通道滤波器.据等离子体的强色散特性,其等效折射率与电磁波频率及等离子体频率等参数有关,因而可以通过改变等离子参数,使一维微波光子晶体缺陷层的谐振频率发生偏移,实现微波光子晶体的可调谐滤波特性.介质层和等离子体层分别采用了时域有限差分(FDTD)算法及分段线性电流密度卷积时域有限差分(PLJERC-FDTD)算法.数值模拟表明,通过改变等离子体频率可以实现滤波通道在光子禁带内较大带宽范围的移动.
关键词:
等离子体
微波光子晶体
可调谐滤波 相似文献
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A band pass THz filter has been presented by the aid of coupling between the waveguides and ring resonator based on metallic photonic crystal slab. The rows of rods are missed and remaining rods in the rows play as a reflector then the position of central rods are rearranged as a ring, the radius of reflector rods and ring resonator is modified in order to optimize the resonance frequency and Q-factor. In addition, 3D-FDTD method is used for simulation results. One of the predominant features of the proposed structure for THz filter is its capability of obtaining a Q-factor of about 333 in the 1 THz resonance frequency with the normalized peak transmission of higher than 0.7, because of high Q-factor cavity based on ring resonator. 相似文献
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Abstract A new optical filter design based on a two-dimensional photonic crystal ring resonator structure with an N-channel model is proposed in this article. This study also shows that modifying the scatter radius and the waveguide width can significantly improve the performance of the original structure, which can solve the mode mismatch problem for output waveguide. Here, an example of a 16-channel photonic crystal ring resonator is provided; wavelength spacing of 1.6 nm and a high quality factor Q of 6,000 were achieved. The optical filter would be a potential key component in the application of dense wavelength division multiplexer devices. 相似文献
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Abstract A detailed theoretical analysis is presented to characterize wave propagation at 1,550 nm inside a glass (SiO2) microring resonator implemented using photonic crystal technology. A photonic crystal reflection is used at each microring resonator corner to enhance the bending efficiency. The characteristics of both photonic crystal beam splitter and microring resonator bending losses are analyzed and investigated using both effective refractive index and finite difference time domain methods. Analytical expressions are also derived to describe the field enhancement inside the microring resonator, the transfer function of the microring resonator, and the main parameters characterizing the resonator such as resonator band width and quality factor. The analysis is also extended to characterize a drop filter implemented using photonic crystal-based microring resonator. The results indicate clearly that the effective refractive index method can give accurate results if one starts the calculations with finite difference time domain-estimated beam splitter parameters. Further, bending efficiency as high as 99% can be obtained using a ten-post layer photonic crystal mirror at each microring resonator corner. 相似文献
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In this paper using elliptical resonant ring we proposed a channel drop filter based on photonic crystal structures suitable for optical communication applications. The drop efficiency and the quality factor of our proposed filter is 100% and 647. We also investigated the optical properties of different configurations of the proposed photonic crystal ring resonator such as vertical ring, dual ring and triple ring structures. According to the results different configurations show different optical properties, so for vertical, double and triple ring configurations the quality factor will be 387, 865 and 1559, respectively. 相似文献
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Behnam Saghirzadeh Darki 《Optics Communications》2010,283(20):4099-4103
The optical channel drop filters (CDFs) based on photonic crystals (PCs) are believed to be the essential components for compact photonic integrated circuits and WDM systems. One of the promising designs for a PC-CDF is based on the photonic crystal ring resonators (PCRRs). In this study, different parameters of a PCRR based CDF is optimized by using the particle swarm optimization (PSO) method in conjunction with the numerical method of two-dimensional (2D) finite-difference time-domain (FDTD) in a square lattice dielectric-rod 2D-PC. Hence a PC-CDF with ideal drop efficiency, large free spectral range (FSR) and acceptable quality factor will be proposed. 相似文献
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Xiaoyong Hu 《Physics letters. A》2008,372(3):333-339
A tunable multichannel filter is demonstrated theoretically based on a one-dimensional photonic crystal heterostructure containing permeability-negative material. The filtering properties of the photonic crystal filter, including the channel number and frequency, can be tuned by adjusting the structure parameters or by a pump laser. The angular response of the photonic crystal filter and the influences of the losses on the filtering properties are also analyzed. 相似文献
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We propose optical cross connect filters using photonic crystal ring resonators coupled waveguide crossings. We investigate the properties of this component numerically by using the finite-difference time-domain method. Our simulations reveal that the photonic crystal based cross connect filter has more than 92% normalized transmission. Extending our concept for cross connection applications, we demonstrate a 1 × 2 PC-based cross connect filter which utilizes a heterostructure. In this filter, at the resonance of each ring resonator, the normalized power transferred to the related waveguide of the two drop waveguides is found to be more than 91%. 相似文献
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Analysis of a second-order polarization-independent filter made of a single ring resonator and a Sagnac interferometer 总被引:1,自引:0,他引:1
Fufei Pang Feng Liu Xiuyou Han Haiwen Cai Ronghui Qu Zujie Fang 《Optics Communications》2006,260(2):567-570
A novel second-order polarization-independent filter made of a single ring resonator and a Sagnac interferometer (SRRSI) is proposed, and its filtering characteristics are investigated. By using birefringence in waveguide, a single ring resonator can be used to synthesize a filter with second-order response. Analytical formulas are derived for characteristics of the SRRSI varied with waveguide parameters, such as the coupling coefficient; and the critical condition of a second-order Butterworth filter is given. The influence of loss in the ring resonator is also analyzed. 相似文献