共查询到17条相似文献,搜索用时 218 毫秒
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首先介绍了光子晶体的原理,以及光子晶体波导在现代光通信中的应用.设计了一种新型的光子晶体慢光波导结构,基于麦克斯韦方程利用有限时域差分法对光子晶体慢光波导的色散关系进行分析,并利用FDTD进行仿真验证. 相似文献
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设计了一种新型一维光子晶体慢光波导结构。在常规波导一侧进行了特殊的设计,使波导具有周期性结构,从而具有特殊的色散关系,获得慢光效应。基于麦克斯韦方程利用平面波展开法对光子晶体慢光波导的色散关系进行了分析,获得了波导模以及相应的慢光频率。并利用时域有限差分法(FDTD)对脉冲在波导的传播进行了时域上的模拟,对慢光效应进行验证。 相似文献
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采用克尔型非线性材料为光子晶体的介质柱,构建线缺陷耦合腔波导。利用非线性有限时域差分法(NL-FDTD)进行模拟仿真,并获得最佳宽带慢光效果。当群速度达到10-2数量级时,带宽为0.0920,比线性光子晶体耦合腔波导慢光带宽提高五倍,而且群速度色散降低两个数量级,实现了低群速度下更宽带宽和更低色散的慢光波导。 相似文献
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研究了线缺陷光子晶体波导中的慢光现象。运用平面波展开法对线缺陷光子晶体波导结构进行了模拟计算,分析了填充因子作为敏感结构参量,其变化对色散性质和群速度的影响。发现光子晶体的填充因子决定了光子晶体带隙中导模的传输特性。随着填充因子的增加,光子晶体波导中的群速度先增大再减小。可以证明,通过改变光子晶体的填充因子,群速度可以达到0.01c以下。 相似文献
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二维三角晶格介质柱光子晶体线缺陷波导慢光研究 总被引:3,自引:0,他引:3
以二维三角晶格介质柱光子晶体线缺陷波导为研究对象,通过平面波展开(PWE)法对光在波导中传输时的慢光特性进行了仿真分析,发现光子晶体的填充因子以及线缺陷中的柱子半径大小决定了慢光导模在光子带隙中的传输特性.随着填充因子的增大,光子晶体波导的导模群速度迅速减小.缺陷柱的半径大小对导模群速度的影响要强于填充比.通过调整填充因子和缺陷柱半径,得到了导模群速度小于0.01c的波导结构.结合慢光导模的群速度色散(GVD)特性分析,发现极慢光区域的GVD值位于105~106量级,能够保证光的高效传输. 相似文献
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为了设计能够传输宽带低色散慢光的光子晶体波导,以三角晶格圆形介质柱光子晶体结构为基础,使用圆形散射元和椭圆形散射元进行周期性排列,采用平面波展开法对所设计的耦合腔波导进行了仿真分析。结果表明,调整缺陷行椭圆形散射元长轴Ra可以使导模最大群速度从0.035c降低到0.01c,调节缺陷行短轴Rb的值,可以再次降低导模群速度;通过改变微腔周围第1排两种散射元的面积比,能够得到最大群速度0.0065c,波长范围为3.25nm的低色散慢光;将所设计的耦合腔应用于光缓存中,计算得出缓存时间为76.82ps,存储容量达到了15.56bit。这项研究对新型光子晶体慢光器件的设计和应用具有参考意义。 相似文献
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We have designed and fabricated waveguides that incorporate two-dimensional (2-D) photonic crystal geometry for lateral confinement of light, and total internal reflection for vertical confinement. Both square and triangular photonic crystal lattices were analyzed. A three-dimensional (3-D) finite-difference time-domain (FDTD) analysis was used to find design parameters of the photonic crystal and to calculate dispersion relations for the guided modes in the waveguide structure. We have developed a new fabrication technique to define these waveguides into silicon-on-insulator material. The waveguides are suspended in air in order to improve confinement in the vertical direction and symmetry properties of the structure. High-resolution fabrication allowed us to include different types of bends and optical cavities within the waveguides. 相似文献
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Jing Ma Chun Jiang 《Quantum Electronics, IEEE Journal of》2008,44(8):763-769
In this paper, an asymmetric photonic crystal (PC) waveguide is proposed for slow light transmission. A row of air holes is removed to form a line-defect waveguide, and the lateral symmetry of the waveguide is broken by shifting the holes in the PC cladding on one side along the waveguide axis. Two structural parameters are carefully adjusted: the amount of shift compared with the array of holes in the cladding on the other side, and the radius of the holes closest to the waveguide core in the shifted PC cladding. In the asymmetric waveguide, it is possible to obtain flat band modes with low group velocity (c/50) and low dispersion (on the order of 104 ps2/km) over a signal bandwidth of 40 GHz. The delay-bandwidth product (DBP) of the proposed slow-light device is analyzed and compared with the DBP of the PC waveguides reported in literatures. We find that our structure yields a significant increase in DBP, and improves the effective bandwidth in which we can obtain slow modes with both low group velocity and vanishing dispersion. 相似文献
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Unidirectional waveguides and slow light waveguides both play the key roles in the modern communication system. The unidirectional waveguides do not support slow light. The traditional slow light waveguides are always limited to the group velocity dispersion. To combine both the functionalities of unidirectional transmission and slow light into one waveguide, we add a surface defect into unidirectional waveguide to modulate the odd mode dispersion. Through a structure optimizing, a dispersionless and slow unidirectional waveguide is obtained. The waveguide with compound functionalities is confirmed through the frequency-domain and time-domain simulations. 相似文献
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Baba T. Motegi A. Iwai T. Fukaya N. Watanabe Y. Sakai A. 《Quantum Electronics, IEEE Journal of》2002,38(7):743-752
Straight single-line defect optical waveguides in photonic crystal slabs are designed by the finite difference time-domain method and fabricated into a silicon-on-insulator (SOI) wafer. By employing an airbridge structure, clear light propagation for both polarizations is observed without any leakage along the waveguide. This experimental result is well explained by photonic bands of pure guided modes. Minimum propagation loss is estimated to be 11 dB/mm. This value is lower than that reported so far for three-line-defect waveguides with an SOI slab structure and almost comparable to that for an index confinement waveguide with a rectangular Si core. This propagation loss is dominated by the scattering loss by some irregularities. However, photonic crystal waveguides have the possibility of an essential lower scattering loss than in the index confinement waveguide because of the inhibition of radiation modes by the photonic bandgap 相似文献
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The Bloch mode propagation through the chirped periodical structure is defined by its local dispersion relation. In a slowly varying structure its time delay is the integral of the local inverse group velocity along the propagation direction. The integration can be strongly simplified for linearly chirped structures if the assumption is made that the local dispersion relation is just a scaled and shifted version of the dispersion relation at the input. This assumption leads to exact solutions for the structures with locally uniaxial deformation and provides a good approximation for arbitrary structures with small chirps. The approach is demonstrated for high index contrast chirped Bragg mirrors and complicated photonic crystal waveguide structures, including coupled waveguides and a slow group velocity waveguide. 相似文献