共查询到18条相似文献,搜索用时 125 毫秒
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在光波导模场分布高斯近似条件下,根据星形光波导耦合器的耦合特性,推导出了基于累加运算和卷积运算近似表达的阵列波导光栅梳状带通滤波器光谱响应效率的函数表达式。给出了阵列波导光栅梳状带通滤波器光谱响应效率曲线的半最大值全宽度和阵列波导光栅梳状带通滤波器的通道中心波长的光谱响应度与器件参数的关系。在输入信号光谱分布高斯近似条件下,给出了阵列波导光栅梳状带通滤波器信号通道传输效率的计算表达式和输入信号光谱宽度对阵列波导光栅梳状带通滤波器信号通道输出特性的影响。给出了物理意义明确的函数表达式,它们可为快速分析阵列波导光栅梳状带通滤波器的特性提供理论基础。 相似文献
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湍流大气传输高斯谢尔光束的到达角起伏 总被引:13,自引:10,他引:3
研究了在弱大气湍流起伏环境下以窄带宽高斯谢尔光束为激光光源的大气通信问题,分析了大气湍流强度和光源空间相干度对通信光束到达角起伏的影响.采用窄带宽光场的交叉谱密度函数代替光场互相干函数的近似方法和采用包含大气湍流内外尺度的简化折射率谱密度函数,得出了湍流大气中传输高斯谢尔光束的波结构函数(WSF) 和到达角起伏方差解析近似关系.分析表明,光源的空间相干度和传输光束的湍流扩展是影响高斯谢尔光束的相位起伏结构函数和传输光束到达角起伏的重要因素. 相似文献
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AWG中波导间耦合造成的相位畸变的分析 总被引:1,自引:1,他引:0
用(1,1)阶Pad啨近似的广角BPM计算了阵列波导光栅(AWG)中由于阵列波导间耦合造成的相位畸变以及由于相位畸变引起的相位误差分别考虑了光从中心/非中心输入波导入射两种情况结果表明,波导间的耦合会造成显著的相位畸变,但由此引起的相位误差却很小,光从中心输入波导入射时对应的相位误差10-3rad,从非中心输入波导入射时的相位误差约为10-2rad针对波导阵列边缘效应引起的相位畸变,设计AWG结构时,在阵列部分两侧增加了边缘辅助波导结构,从而消除了边缘效应,使得边缘阵列波导对应的相位误差从10-1rad量级减小为10-3(10-2)rad量级. 相似文献
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半导体激光器远轴光束的准直特性研究 总被引:6,自引:2,他引:4
对半导体激光器光束准直场的研究具有重要的意义,半导体激光器的远轴模型能精确描述其发出的光束。根据瑞利索末菲衍射公式,利用稳相法得出了半导体激光器远轴光束经过透镜准直后的场分布解析表达式。根据该表达式可以得出如下结论:准直后光束在两个方向上的光斑大小与透镜焦距成正比,且与传输距离无关,沿轴光强与波导尺寸参量和准直透镜焦距有关,且与透镜焦距成平方反比关系,在传输距离较短的情况下,准直光场相位分布近似为球面,传输距离较长时,光场相位近似为平面.这些结论在工程应用中具有重要的价值。 相似文献
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聚合物脊形光波导的变分有效折射率法分析 总被引:2,自引:1,他引:1
聚合物脊形光波导是聚合物集成光电子器件的重要构成单元.利用有效折射率法计算聚合物脊形光波导的横向折射率分布及有效折射率,将各区域中的光场分布近似用分段函数表达.基于导模满足的标量波动方程,利用变分法确定变分参量,以求得准确的横向光场分布.对聚合物脊形多模光波导基模和高阶模的色散特性与横向场分布进行分析,研究了波导结构参数对色散特性的影响,计算出TM基模和高阶模的光场分布,得出了聚合物脊形光波导的单模传输条件.研究表明,该方法计算量小、精度高,对聚合物光电子器件中脊形光波导的理论分析与设计优化提供了简单高效的方法. 相似文献
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An efficient and accurate three-dimensional (3D) hybrid modeling, which combines a 3D beam propagation method (BPM) and the two-dimensional (2D) Kirchhoff–Huygens diffraction formula, is developed to simulate the field propagation in an arrayed waveguide grating (AWG) demultiplexer. The 2D Kirchhoff–Huygens diffraction formula is used for the simulation of the light propagation in the free propagation regions (FPRs). A 3D BPM in a polar coordinate system is used to simulate the light propagation in the transition region between the input FPR and the arrayed waveguides so that the coupling coefficients for the arrayed waveguides are calculated conveniently and accurately. For the simulation in the transition region between the arrayed waveguides and the output FPR, only the central arrayed waveguide and several adjacent ones are needed in the computational window of a standard BPM and thus the computation efficiency is improved. Finally, a flat-top AWG is designed and fabricated to verify the reliability of the present simulation method. The calculated and measured spectral responses are in a good agreement. 相似文献
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Kenichi Masuda Atsushi Tate Mariko Ishida Takanori Suzuki Hiroyuki Tsuda 《Optical Review》2006,13(4):184-188
We propose a beam steering type optical switch employing a phase shifter. It consists of collimating waveguide mirrors, an
arrayed-waveguide which has deep trenches incorporating polymer materials, and input/output waveguides. The incident light
is guided to the front mirror, where it is then collimated, and input to the arrayed waveguide. The number of trenches filled
with polymer linearly increases in order. The refractive index of the polymer can be controlled with temperature, and the
propagation direction of the output light from the arrayed waveguide can also be controlled. A switch with 15 waveguides in
the array has been fabricated. The chip size is about 2:5 × 9:0 mm2, the insertion loss is 10 dB, and the extinction ratio is about 10–13 dB. 相似文献
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M-Z光波导是聚合物电光调制器的重要结构单元。利用有效折射率法计算聚合物脊形波导的横向折射率分布,将三维光波场传播简化为二维传播。从导模满足的标量波动方程出发,结合透明边界条件,采用Crank-Nicholson差分格式,得出有限差分束传播法的基本计算格式。通过对M Z型波导结构中TM模的传播及损耗特性进行理论分析,系统地研究了脊宽、分支角等结构参数对损耗的影响。研究表明,有效折射率法与二维有限差分束传播法的结合可以较好地解决脊形M Z波导的设计问题。该方法具有精度高、计算量小及效率高等优点,为聚合物电光调制器的制备提供了理论依据。 相似文献
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Abstract This article proposes a silicon-based arrayed waveguide grating operating in two wavelength bands simultaneously with central wavelengths of 1,550.12 nm and 1,310.12 nm. If input light to an arrayed waveguide grating consists of wavelengths around 1,550.12 nm, the proposed system will act as a four-channel demultiplexer with channel spacing of 0.8 nm. On the other hand, when input wavelengths are distributed around 1,310.12 nm, the same arrayed waveguide grating will divide the input to seven channels with channel spacing of 0.33 nm. 相似文献
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光通信中波分复用技术是解决通信网络瓶颈的有效手段,近年来得到很大发展。以平面波导波分复用器件为核心的密集波分复用技术已经得到成功商用。蚀刻衍射光栅是平面波导密集波分复用器件中很有发展潜力的一种。原有蚀刻衍射光栅采用罗兰圆设计,输入输出在圆弧曲线上由条形波导引出;而平场输入/输出的蚀刻衍射光栅在很多应用中可以省去制作输入输出波导,大大简化制作工艺,同时能够保持良好的线性色散和聚集效果。给出了平场输入和输出蚀刻衍射光栅的设计方法,并利用标量衍射理论对设计的结果进行模拟,验证了平场输出蚀刻衍射光栅具有很好的分波效果。 相似文献
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A triplexer is fabricated based on SOI arrayed waveguide gratings (AWGs). Three wavelengths of the triplexer operate at different diffraction orders of an arrayed waveguide grating. The signals of 1490nm and 1550nm, which are input from central input waveguide of an AWG, are demultiplexed and the signal of 131Onto, which is input from central output waveguide of an AWG, is uploaded. The tested results show that the downloaded and uploaded signals have fiat-top response. The insertion loss is 9 dB on chip, the nonadjacent crosstalk is less than -30 dB for 1490nm and 1301 nm, and is less than -25 dB for 1550nm, the 3dB bandwidth equates that of the input light source. 相似文献
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《Optics Communications》2002,201(1-3):45-53
First some important parameters are optimized for the structural design of a polymer arrayed waveguide grating (AWG) multiplexer around the central wavelength of 1.55 μm with the wavelength spacing of 1.6 nm. These parameters include the thickness and width of the guide core, mode effective refractive indices and group refractive index, diffraction order, pitch of adjacent waveguides, length difference of adjacent arrayed waveguides, focal length of slab waveguides, free spectral range (FSR), the number of input/output (I/O) channels, and that of arrayed waveguides. Then the bent angles, radii and lengths of all the input/output channels and arrayed waveguides are determined. Finally, a schematic waveguide layout of this device is presented, which contains 2 slabs, 11 input channels, 11 output channels, and 91 arrayed waveguides. 相似文献