共查询到19条相似文献,搜索用时 125 毫秒
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为了分析结构参量对正负折射率材料1维光子晶体缺陷模的影响,利用传输矩阵法计算了基于正负折射率材料含正折射率缺陷1维光子晶体B(AB)m(ACB)n(AB)mB的透射谱,分析了各参量对该结构1维光子晶体缺陷模的影响,并用波动理论定性分析了多通道滤波器形成的原因。结果表明,在各介质层的光学厚度绝对值都为0/4的情况下,每个禁带中都有n个超窄的透射峰,相邻两个透射峰间距比相同结构下正折射率情况的宽;当n=1时,随着C层介质光学厚度以0/4的k倍增加,透射谱中同一禁带内出现了k条透射峰;当n2时,透射谱中同一禁带内出现了nk条透射峰。该研究结果对可调多通道滤波器的设计和研究有一定的参考价值。 相似文献
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为了分析研究1维光子晶体的结构参量对其能带结构的影响,并把这种影响作用应用到滤波器的设计中,采用传输矩阵法、利用MATLAB仿真软件,对不同结构参量的1维光子晶体的能带结构进行了计算仿真,分别得到了不同周期数、不同介质层厚度、不同介质折射率的1维光子晶体的能带分布图,进一步分析比较,得出了1维光子晶体的结构参量对其能带结构的影响。结果表明,较大的周期数可以使1维光子晶体的禁带边缘更加陡峭,通带透射性增强,能带分布更加分明;介质层厚度可以调节光子晶体的能带分布情况及能带宽度;介质折射率比值可以改变禁带宽度,禁带宽度随介质折射率比值的增大而增大。这些结果对宽带带阻滤波器的设计是有帮助的。 相似文献
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应用等效折射率模型研究光子晶体光纤 总被引:11,自引:4,他引:7
应用等效折射率模型研究了光子晶体光纤(PCF)的传播特性.介绍了光子晶体光纤的等效折射率模型.通过求解标量波动方程得到了光子晶体光纤包层基空间填充模的模式折射率,利用阶跃光纤的理论来研究光子晶体光纤的导模特性.应用此模型对不同结构光子晶体光纤包层区的等效折射率与波长的关系进行了讨论.包层区等效折射率与芯子的折射率差随波长的增加而增大,并由此阐述了光子晶体光纤的单模特性.数值分析得到光子晶体光纤的基模的模式折射率,并由此研究了光子晶体光纤的波导色散与结构参量的关系.分析表明,光子晶体光纤的波导色散随空气孔孔距的变化符合Maxwell方程的比例性质.空气孔的相对孔径对波导色散有重要的影响.这些分析表明光子晶体光纤具有可以灵活设计其色散特性的潜在应用前景. 相似文献
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飞秒激光直写玻璃波导是快速制备三维集成光子芯片的一种重要手段,波导有效折射率的准确测量对于设计光子器件意义重大。设计并制备了一种断臂马赫-曾德尔干涉仪(MZI)结构对玻璃波导有效折射率进行原位精密测量。激光在断线区域和波导内的有效折射率不同,在传输相同长度下产生一定的相位差,最终导致不同的干涉结果。对断臂MZI结构的相位干涉结果进行处理,得到激光直写玻璃波导的有效折射率为1.504+7.7×10?4。利用RSOFT软件光束传播算法对器件进行模拟仿真,仿真结果与实验吻合良好。该精确测量玻璃波导有效折射率的方法对于提升光子芯片设计与制造能力具有重要意义。 相似文献
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基于有效折射率法建立了窄脊型波导数值计算模型,通过实验研究了InGaAs量子阱窄脊型波导半导体激光器偏振特性与横模之间的关系。根据理论计算,脊型波导中类TM模式在慢轴方向的有效折射率差更大,类TM模式的限制因子比类TE模式的限制因子更大、更容易出现慢轴高阶模式;而随着脊型波导的高度增加,快轴高阶模式被截断,类TE00模式的限制因子逐渐增加至与类TM00模式相近,慢轴高阶模式因其大的散射损耗被抑制,理论上可实现高偏振度、高光束质量激光输出。在实验方面,利用量子阱材料的增益偏振特性,通过脊型高度与宽度的设计,制备了高偏振度、基横模的窄脊型波导半导体激光器。 相似文献
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构建了基底介质为SiO2、表面覆层介质为TiO2 的二维光子晶体,采用严格耦合波法分析了二维光子晶体的窄带光学传输特性。分析了二维光子晶体的晶格周期、波导层的折射率及厚度对其反射光谱的影响。分析结果表明:当光子晶体的晶格周期和波导层介质厚度为常数时,随着波导层介质折射率的增大,光子晶体的反射峰值波长红移,且波导层折射率与反射峰值波长呈线性关系。当光子晶体波导层介质折射率为常数时,波导层厚度增大或光子晶体晶格周期的增大都会引起光子晶体反射峰值波长增大,但这两个参数与反射峰值波长只是在一定的变化范围内为线性关系。此种结构的二维光子晶体覆层表面吸附分布不均匀的介质时,通过分析光子晶体的呈现光谱可获得其表面吸附介质的不均匀特性。 相似文献
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Sugimoto Y. Ikeda N. Carlsson N. Asakawa K. Kawai N. Inoue K. 《Quantum Electronics, IEEE Journal of》2002,38(7):760-769
An AlGaAs-based near-infrared 2-D photonic crystal (PC) with an air-bridge structure featuring defect waveguides has been developed. For the sample without defect waveguides, measurements of the optical transmission characteristics in the wavelength range from 850 nm to 1100 nm showed a deep attenuation due to a bandgap with 30-35 dB attenuation and transmittance of nearly 100% for the guided modes. Optical propagation properties of defect waveguides were obtained by two methods: measurements of transmission spectra and plan-view observations of the optical beam trace along the waveguide with an infrared-vidicon camera. 3-D finite-difference time-domain simulations for the band structure and transmission spectra in the air-bridge slab with and without defect waveguides have revealed the appearance of four defect propagation modes specific to the defect waveguide, between two slab modes for the defect-free photonic crystal slab. These defect modes were experimentally identified in the measured transmission spectra 相似文献
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Notomi M. Shinya A. Yamada K. Takahashi J.-I. Takahashi C. Yokohama I. 《Quantum Electronics, IEEE Journal of》2002,38(7):736-742
We experimentally demonstrate the structural tuning of the waveguiding modes of line defects in photonic crystal (PC) slabs. By tuning the defect widths, we realized efficient single-mode waveguides that operate within photonic band gap frequencies in silicon-on-insulator PC slabs. The observed waveguiding characteristics agree very well with three-dimensional finite difference time-domain calculations. We also directly measured the propagation loss of the line defect waveguides and obtained a value of 6 dB/mm 相似文献
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This paper deals with the two dimensional (2-D) infrared photonic crystal slab with an air-bridge structure featuring defect waveguides in which the optical propagation properties were obtained by measurements of transmission spectra. 3-D finite-difference time-domain (FDTD) simulations have revealed the appearance of four defect propagation modes for the band structure and transmission spectra in the air-bridge slab. These defect modes were experimentally identified in the measured transmission spectra. 相似文献
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一种缓变结构一维光子晶体的缺陷模研究 总被引:3,自引:2,他引:1
利用传输矩阵方法,研究了单折射率层缓变准周期结构一维光子晶体存在不同缺陷时的缺陷模。结果表明,当该准周期结构中存在缺陷时,引入了缺陷模,且缺陷模与缺陷层的位置和结构参数相关。缺陷层不同,缺陷模的位置及共振透射峰也不同。随着缺陷层光学厚度的增大,缺陷模波长向长波方向移动。 相似文献
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Galli M. Bajoni D. Belotti M. Paleari F. Patrini M. Guizzetti G. Gerace D. Agio M. Andreani L.C. Peyrade D. Chen Y. 《Selected Areas in Communications, IEEE Journal on》2005,23(7):1402-1410
The dispersion of photonic modes in one-dimensional (1-D) and two-dimensional (2-D) patterned silicon-on-insulator (SOI) waveguides, also containing line defects, is fully investigated both above and below the light line. Quasi-guided (radiative), as well as truly guided modes are probed by means of angle- and polarization-resolved microreflectance and attenuated total reflectance measurements. For the 1-D case, the sharp resonances observed in reflectance spectra are analyzed in terms of the Airy-Fano model, and the measured linewidths are shown to be very close to theoretical predictions. In the 2-D lattices containing W1 line defects the presence of a supercell repetition leads to the simultaneous excitation of defect and bulk modes which are folded in a reduced Brillouin zone. The measured dispersion is in very good agreement with full three-dimensional calculations based on expansion on the waveguide modes, indicating that a deep understanding of the propagation properties of patterned SOI waveguides is achieved. 相似文献
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Jian Yang Carlberg U. Kildal P.-S. Kehn M.N.M. 《Microwave Theory and Techniques》2004,52(6):1615-1621
A fast mode analysis for waveguides of arbitrary cross section with multiple regions is presented in this paper. The analysis is based on a spectrum of two-dimensional (2-D) solutions with application of asymptotic waveform evaluation, which requires only several 2-D solutions in searching for the propagation modes and calculating the field distribution of the modes in waveguides. The boundaries of waveguides can be modeled by perfect electric conductors, perfect magnetic conductors, dielectric materials, and asymptotic strip boundary conditions. By this modeling, one can also analyze the waveguides with the soft and hard surfaces. The method is excitation dependent, which provides a tool to analyze the response of different modes to different excitations. No existence of spurious modes is experienced by using this method. The verification and comparison of the numerical results with analytical, published data, and measurements are also presented in this paper. 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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采用一种基于三电场分量的全矢量有限元法,其中引入了完善匹配层(PML)吸收边界条件,分析由梯形截面硅基垂直多槽纳米线构成的平行定向耦合器.考虑了波导侧壁倾角、耦合波导间距、槽宽及槽折射率的变化对定向耦合器性能的影响.给出了准TE与准TM偶、奇模有效折射率、耦合长度及模场分布,揭示了其模式的混合特性及模场分布特点.分析结果表明,恰当选择结构参数及材料参数,可实现两偏振态下相同耦合长度,定向耦合器在偏振无关条件下工作. 相似文献