一维光子晶体波长可调谐滤波器

介绍了一种将液晶作为缺陷引入到一维光子晶体结构中,实现波长可调谐的滤波器.通过对光子晶体的滤波特性的分析清晰地说明这种光可调谐滤波器的原理和可行性.同时选用手征近晶型液晶,利用电压对这种液晶折射率的调制快于向列液晶的特性,得到符合现在光通信网要求的体积小、阻带区对透光抑制力强、损耗低和开关速度快的可调滤波器.最后,对滤波结构中的重要参数进行了探讨.     

Ultra-compact optical filter in two-dimensional photonic crystal

A design of an ultra-compact in-plane optical add/drop filter is proposed. The filter is formed by two waveguides and one two-mode cavity in a two-dimensional triangular photonic crystal. The simulated results demonstrate good transfer characteristics with a quality factor of about 1700.     

一维光子晶体滤波器的研究进展

光子晶体最显著的特点是抑制某些频率电磁波,产生光子禁带,实现对光子的优良滤波性能.在此介绍了目前一维光子晶体滤波器的基本理论、实验进展以及一维光子晶体滤波器的主要应用类型.     

光子晶体的吸收对光子晶体滤波器设计的影响

引入复折射率并利用特征矩阵法,研究了光子晶体的吸收对滤波通道峰值和半高宽的影响.得出:滤波通道的峰值随光子晶体的消光系数增加而迅速减小.滤波通道的半高宽随消光系数增加而增大.滤波通道的峰值和半高宽都随有吸收的光子晶体的周期数增加而迅速减小.设计光子晶体滤波器时,应选择消光系数尽可能小的材料,并且光子晶体的周期数不宜大.     

光子晶体与光子准晶复合型上下载滤波器

基于二维正方晶格光子晶体与十二重Stamfli型光子准晶提出了单环形腔上下载滤波器及双环形腔串联上下载滤波器.分析并对比了两种上下载滤波器的传输效率随光子准晶介质柱半径及折射率大小的变化规律,且对比了两种上下载滤波器的品质因数随环形腔中心介质柱半径及折射率大小的变化规律.结果表明,双环形腔串联复合型上下载滤波器的性能优于单环形腔复合型上下载滤波器.研究结果将为设计及制备优良上下载滤波器件提供一定指导作用.     

基于二维光子晶体的多频段太赫兹波滤波器研究

基于二维光子晶体,提出一种多频段 太赫兹(THz)波滤波器。在光子晶体中引入3条平行的横向波导,通过改变介质柱的半 径或插入半径较小的介质柱在 相邻波导之间构成耦合区域,使特定频率的THz波从中部波导耦合至上、下侧光子晶体波 导并分别从端口2和1输出, 其余的THz波经中部波导从端口3输出,最终达到多频段滤波的效果。利用时域有限差 分法和平面波展开法对所提出 的器件计算和仿真结果显示,频率为f=3.24和3.75THz的THz波分 别从端口1、2和3输出中,传输效率分 别达到95%和99% ,表明本文结构能很好实现多频段滤波效果。     

带有环形谐振器的T形光子晶体滤波器

提出了一种带有环形谐振器的T形光子晶体滤波器,利用时域有限差分法研究了滤波器传输特性,分析了光子晶体结构参数对其传输特性影响。结果表明：该结构具有可调性开关波长、传输率高及频带宽的特点,在光子晶体集成制作、光通信器件制作等方面具有潜在的应用价值。     

Photonic crystal ring resonator based add-drop filter using hexagonal rods for CWDM systems

In this paper,theoretical analysis of two-dimensional photonic crystal ring resonator(2D PCRR) based add-drop filter(ADF) is presented for coarse wavelength division multiplexing(CWDM) system to drop a channel at 1511 nm using hexagonal rods that are positioned in the square lattice.The 2D finite difference time domain(2D FDTD) method and plane wave expansion(PWE) method are used for obtaining the filter response and band structure of the filter respectively.Close to 100 dropping and coupling efficiencies at 1511 nm and 16 nm of bandwidth are observed through simulation.This is very well meeting the requirement of ITU-T G.694.2 standard,which is specified for metro access and short haul optical networks.The overall size of the proposed filter is 11.4 μm×11.4 μm.It can also be used in integrated optics.     

Ultra-high-Q optical filter based on photonic crystal ring resonator

In this study, a photonic crystal ring resonator with a triangular lattice is used to design an optical filter. The proposed structure is able to filter the central wavelength of 1548 nm with a transmission coefficient of over 95%. Moreover, this structure has an ultra-high-quality factor (Q) of about 1290. With altering the features of the structure including the refractive index, the lattice constant and the radius of the rods in the resonator core, their effects on the central wavelength of the filter, transmission coefficient, quality factor and bandwidth are investigated. The plane wave expansion and finite-difference time-domain methods are used to extract photonic band gap and investigate the photonic behavior of the proposed structure, respectively.     

Degradation-free MOS image sensor with photonic crystal color filter

This letter demonstrates a long-term reliable MOS image sensor equipped with a novel photonic crystal color filter (PC-CF). PCs are periodically structured dielectric media, generally possessing a photonic band gap. In the newly developed PC-CF, it is clarified that the desirable spectral property, i.e., peak wavelength and spectral passband, can be achieved by modifying the thicknesses of the defect layers, which act just like a "defect" in a PC. The spectral characteristics with the peak wavelengths at 450 (blue), at 530 (green), and at 610 nm (red) are realized in this letter. Moreover, the fabricated image sensor guarantees high reliability of longer than 200 000 h and heat resistance of above 300 /spl deg/C.     

Deep notch filter based on liquid-filled photonic crystal fiber

A deep notch filter in a liquid-filled photonic bandgap fiber (PBGF) realized via filling an erbium-doped solid core photonic crystal fiber with high-index liquid is proposed and demonstrated. The numerical investigation indicates that the notch is formed due to avoid-crossing effect between the fundamental mode and LP02 supermodes. The resonance wavelength of the filter can be tuned by adjusting the temperature of the liquid-filled PBGF and shifts toward short wavelength. The blue-shift speed average is 1.3nm/℃.     

A high quality factor photonic crystal channel-drop filter with a linear gradient microcavity

We design a channel-drop filter (CDF) with a linear gradient microcavity in a two-dimensional (2D) photonic crystal (PC). The model of three-port CDF with reflector is used to achieve high quality factor (Q-factor) and 100% channel-drop efficiency. The research indicates that adjusting the distance between reference plane and reflector can simultaneously influence the Q-factor due to coupling to a bus waveguide and the phase retardation occurring in the round trip between a microcavity and a reflector. The calculation results of 2D finite-difference time-domain (FDTD) method show that the designed filter can achieve the drop efficiency of 96.7% and ultra-high Q-factor with an ultra-small modal volume.     

镜像耦合一维光子晶体窄带滤波器设计研究

文章提出准周期一维光子晶体的概念,把一维时域有限差分方法用于一维二元准周期光子晶体构成镜像耦合结构的窄带滤波特性设计研究.数值结果表明,用此结构能实现窄带滤波.进一步研究表明,要实现同一波长的滤波,在其他条件不变时,耦合层的折射率越大,则镜像耦合层厚度越小;在耦合层介质一定时,耦合层厚度决定窄带的位置与带宽;在其他条件一定时,入射角大小决定窄带的位置,入射角度越大,窄带位置越向短波方向移动.     

Optical add-drop multiplexers based on autocloned photonic crystals

We describe and demonstrate the operation of optical add-drop multiplexers (OADMs) based on photonic crystal (PC) structures fabricated by autocloning technology. In these OADMs, a three-dimensional PC structure was utilized as a Bragg reflector. We obtained a drop bandwidth of 2 nm at a wavelength of 1560 nm. We also demonstrate for the first time add and drop operations of the PC-based OADMs in a wavelength-division multiplexing optical transmission system.     

两种光子晶体滤波器性能的比较

利用传输矩阵法,通过分别计算由高折射率介质与金属叠加而成的多层膜和由高、低折射率介质交替排列、中间含有间隔的复式膜的透射率,比较了与这两种膜对应的多层膜滤波器和复式膜滤波器的滤波特性。结果表明:多层膜滤波器的角度宽容性较好,但单色性和透射性较差,此类滤波器适合于入射角变化大,但对单色性和透射性要求不高的情况。而复式膜滤波器的性能恰好和多层膜滤波器的相反,特别适合小角度入射的情况。     

Tunable polarisation-maintaining filter based on liquid crystal photonic bandgap fibre

A tunable and polarisation-maintaining all-in-fibre filter based on a liquid crystal photonic bandgap fibre is demonstrated. Its polarisation extinction ratio reaches 14 dB at 1550 nm wavelength. Its spectral tunability range spans over 250 nm in the temperature range 30?708C. The measured transmission spectrum is compared with that obtained through finite element simulations.     

0.35 THz二维光子晶体带通滤波器设计

设计了一种基于二维光子晶体的太赫兹带通滤波器,通过在线缺陷的光子晶体波导两侧引入对称的点缺陷形成谐振腔,在太赫兹频段实现了较好的带通滤波特性。这种二维光子晶体带通滤波器具备较宽的通带带宽,同时还可以通过增加多组对称点缺陷的方式实现多个谐振腔的级联,进一步提高带外抑制特性,可满足太赫兹通信或雷达系统的应用需求,具有良好的应用价值。     

四元异质结构光子晶体的双通道光学滤波特性

为了设计高品质的光学滤波器,采用传输矩阵法研究四元异质结构光子晶体（ABC）7D（CBA）7的双通道光学滤波特性。结果表明,随着A（或C）介质薄膜光学厚度D_A（或D_C）的增大,滤波器短波通道的滤波品质因子降低,长波通道的滤波品质因子升高;随着B介质薄膜光学厚度D_B增大,滤波器短波通道和长波通道的滤波品质因子均下降;随着D介质薄膜光学厚度D_D增大,滤波器短波通道的滤波品质因子升高,而长波通道的滤波品质因子降低;随着各薄膜介质层光学厚度增大,滤波器双通道均向长波方向红移,但各滤波通道的光透射率均保持100%不变。该研究结果可为光子晶体设计新型光学滤波器件、光学开关等提供参考。     

新型光子晶体四通道滤波器研究与设计

基于光子晶体环形腔缺陷与线缺陷波导之间的共振耦合原理,设计了 一种由新型环形腔和主波导组成的四通道二维三角晶格光子晶体滤波器.运用平面波展开法和时域有限差分法分析了光波在整合结构中的传输特性,并进一步讨论环形滤波器内的内部介质柱半径大小对滤波器传输特性的影响.结果表明:新改进环形的滤波器传输效率达到80％左右.通过实验...