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Based on the present coupled mode theory of the photonic crystal resonator array in this paper,we propose a novel side-coupled waveguide to achieve highly efficient coupling of photonic crystal devices.It is found that the coupling efficiency is sensitive to the interval,the total number and the quality factor of the resonator.Considering the coupling efficiency and the coupling region,we select five resonators with an interval of six lattice periods.By optimizing the structure parameters of the waveguide and resonator,the quality factors of the resonator can be modulated and the coupling efficiency of the side-coupled waveguide reaches 95.47% in theory.Compared with other coupling methods,the side-coupled waveguide can realize efficient coupling with a compact structure,a high level of integration and a low degree of operational difficulties. 相似文献
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Based on the present coupled mode theory of the photonic crystal resonator array in this paper, we propose a novel side-coupled waveguide to achieve highly efficient coupling of photonic crystal devices. It is found that the coupling efficiency is sensitive to the interval, the total number and the quality factor of the resonator. Considering the coupling efficiency and the coupling region, we select five resonators with an interval of six lattice periods. By optimizing the structure parameters of the waveguide and resonator, the quality factors of the resonator can be modulated and the coupling efficiency of the side-coupled waveguide reaches 95.47% in theory. Compared with other coupling methods, the side-coupled waveguide can realize efficient coupling with a compact structure, a high level of integration and a low degree of operational difficulties. 相似文献
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Electro-optical resonant switching in two-dimensional side-coupled waveguide-cavity photonic crystal systems 总被引:1,自引:0,他引:1
Cheng-Yang Liu 《Physics letters. A》2011,375(44):3895-3898
Photonic crystals have many potential applications because of their ability to control lightwave propagation. We have investigated the electro-optical resonant switching in two-dimensional photonic crystal structures. The optical microcavity side coupled with a waveguide composed of a dielectric cylinder in air is studied by solving Maxwell?s equations using the plane wave expansion method and finite-difference time-domain method. The switching mechanism is a change in the conductance of the microcavity and hence modulating the resonant mode and eventually resonant switching is achieved. Such a mechanism of switching should open up a new application for designing components in photonic integrated circuits. 相似文献
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通过使用正方格介质柱二维光子晶体设计了带有环形谐振器的一种插分滤波器ADF(add drop filter)结构,该结构具有1个输入端口和2个输出端口,采用时域有限差分法研究了带有1个环形谐振器和2个环形谐振器的ADF结构传输性能。结果表明:该ADF结构在第三通信窗口具有优良的滤波作用,能够根据需要将电磁波信号沿着波导向前后上下4个方向传输,ADF结构还具有可调性开关波长、宽频带、高传输率等特点,在光子晶体集成化、光器件制作等方面具有潜在价值。 相似文献
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This paper presents a novel in-plane photonic crystal channel drop filter.The device is composed of a resonant cavity sandwiched by two parallel waveguides.The cavity has two resonant modes with opposite symmetries.Tuning these two modes into degeneracy causes destructive interference in bus waveguide,which results in high forward drop efficiency at the resonant wavelength.From the result of numerical analysis by using two-dimensional finite-difference time-domain method,the channel drop filter has a drop efficiency of 96% and a Q value of over 3000,which can be used in dense wavelength division multiplexing systems. 相似文献
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Baldycheva A Tolmachev VA Perova TS Zharova YA Astrova EV Berwick K 《Optics letters》2011,36(10):1854-1856
We report on what is believed to be the first example of an ultrawide, bandpass filter, based on a high-contrast multicomponent one-dimensional Si photonic crystal (PC). The effect of the disappearance of a limited number of flat stopbands and their replacement with extended passbands is demonstrated over a wide IR range. The passbands obtained exhibit a high transmission of 92% to 96% and a substantial bandwidth of 1800 nm, which is spectrally flat within the passband. The multicomponent PC model suggested can be applied to the design of any micro- or nanostructured semiconductor or dielectric material for application across a wide spectral range. 相似文献
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We propose an add-drop filter consisting of two adjacent waveguides carved into a two-dimensional photonic crystal that is etched through a standard guiding structure. This filter is based on distributed energy transfer via the frequency-selective intermediate conversion of the fundamental guided mode to a high-order low-group-velocity mode. This geometry circumvents the fabrication sensitivity on the single-hole scale of previous cavity-based designs. Combining distributed energy transfer and reduced group velocity preserves compactness. The design is analytically optimized with a coupled-mode approach. 相似文献
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Fabrication of two-dimensional organic photonic crystal filter 总被引:1,自引:0,他引:1
A high quality two-dimensional photonic crystal filter made of polystyrene is fabricated by the method of focused ion beam
etching. Scanning electron microscopy (SEM) and transmittance spectrum are used to characterize the properties of photonic
crystal filter. The measured transmittance spectrum is in agreement with the theoretical one. It is found that the filtering
properties of photonic crystal filter, including the position and quality factor of optical channel, can be tuned by adjusting
the width of line defect.
PACS 42.70.Qs; 61.46.+w; 81.15.-z 相似文献
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光子晶体多通道可调谐滤波器的理论研究 总被引:3,自引:1,他引:3
为了实现光子晶体的多通道滤波,对设计出的一维掺杂光子晶体进行了数值计算和理论分析。结果表明:多通道透射峰的波长与空气膜厚度呈线性变化,不同厚度的空气膜可以截到数目不同的透射峰,多通道透射峰的半高宽随光子晶体折射率n2的增加而减小。以此为基础,设计出滤波通道波长的可调范围达60nm,滤波通道半高宽的可调范围为1nm~5nm,滤波通道透射峰值大于0.98的一维光子晶体三通道可调谐滤波器。 相似文献
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A tunable filter made from a two-dimensional polystyrene photonic crystal is fabricated by focused ion-beam etching. The pump and probe scheme is adopted to measure tunability based on the picosecond optical Kerr effect. The response time of the tunable filter, approximately 10 ps, is within the measurement resolution. The maximum shift of optical channels is estimated to be 6 nm under excitation of 15.9 GW/cm2 pump intensity, which is in agreement with the theoretical prediction. 相似文献
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In this paper,a sidelobe suppression method using nonuniformly spaced array with aperture apodization processing is proposed for underwater acoustic imaging in near field,which is studied both in theory and experiment.The focused beamforming based on spherical wave propagation theory is used in the method.Firstly,the nonuniform array with low sidelobe is designed for suppressing the sidelobe of one-way beam pattern by spacing perturbation.Then, applying the aperture apodization technique to underwater acoustic imaging,the different size apertures for transmitting and receiving are used for further suppressing the sidelobe of two-way beam pattern.The experimental results from water tank show that the proposed method can suppress the sidelobe more effectively only with fractional mainlobe width increase.Since the method is simple-realized,the imaging system can be simplified as well as achieving improved performance. 相似文献
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提出了一种近场条件下采用不等间隔阵并进行孔径变迹处理的水下声成像旁瓣抑制方法,并进行了理论和实验研究。考虑以球面波传播理论为基础的聚焦波束形成,首先通过阵元位置微调,设计了可实现低旁瓣的不等间隔阵,从单程波束响应上降低旁瓣;然后,将孔径变迹处理方法应用于水下声成像中,全部阵元用于接收,部分阵元用于发射,从双程波束响应上进一步降低旁瓣。通过水池实验对所提出的方法进行了验证。结果表明:采用不等间隔阵并进行孔径变迹处理可以更为有效地降低旁瓣,而主瓣仅有小量展宽,且该方法工程应用简便易行,在改善成像质量的同时降低了系统复杂度。 相似文献
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根据BaF2晶体闪烁光快、慢成分波段的不同,设计并制备了用于抑制该晶体闪烁光慢成分的Al2O3/MgF2/Al/MgF2…光子带隙膜系。实验结果显示:加载光子带隙膜系的BaF2晶体,其闪烁光快/慢成分比提高80倍以上;经剂量为1×105 Gy的60Co γ射线辐照后,其透射光谱、发射光谱和发光衰减时间谱没有明显的变化,这表明由光子带隙膜系与BaF2晶体所构成的快闪烁器件不仅可有效避免慢成分的干扰,而且还具有很强的抗γ辐射性能。 相似文献
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Highly tunable photonic crystal filter for the terahertz range 总被引:1,自引:0,他引:1
By use of an incipient ferroelectric, SrTiO3, as a defect material inserted into a periodic structure of alternating layers of quartz and high-permittivity ceramic, thermal tuning of a single defect mode over the entire lowest forbidden band was obtained. The tunability of this compact structure reached 60%. 相似文献
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本文研究了铁氧体磁性材料应用于太赫兹波导器件的可行性. 利用铁氧体磁性材料的磁导率随外磁场改变而变化的性质,设计出了一种新颖的磁控连续可调谐太赫兹滤波器和开关. 利用平面波展开法(plane wave expansion,PWE)和时域有限差分法(finite difference time domain,FDTD)计算了二维磁光子晶体中外磁场变化对带隙位置和宽度的影响,结果显示应用该结构实现的滤波器和开关具有良好的性能.
关键词:
磁光子晶体
铁氧体
太赫兹 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