基于SOI的高性能波导交叉单元研究

发布时间：2018-02-28 04:54

本文关键词： 波导交叉多模干涉桥式结构锥形结构　出处：《华中科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：现代光子技术的发展对器件的集成性，片上器件密度、功能、性能等要求越来越高，这使得单芯片上光波导之间交叉次数大大增加。同时，SOI（Silicon On Isolator）材料作为光集成研究的热点材料具有导光特性好，，对光的限制作用强并且与标准的CMOS工艺完全兼容等优点，然而SOI大的芯/包折射率差使其导模的空间角很大，从而导致光在波导交叉的部分会产生显著的散射。SOI光波导单次直接交叉的损耗和串扰分别为1~1.5dB和-10~-15dB，大量交叉产生的损耗和串扰对单芯片而言将难以接受。为解决上述问题，本论文试图设计一种结构紧凑，低交叉损耗、低串扰的SOI光波导交叉方案，同时能够与半导体工艺兼容。本论文主要研究内容如下：（1）构建了无损耗的正锥形（adiabatic taper）与倒锥形结构（adiabatic inverse taper），分析了倒锥形结构中模场宽度、有效折射率的变化情况；（2）建立了基于多模干涉结构的波导交叉单元并用Comsol进行了仿真。在尺寸为13m13m的情况下损耗为0.22dB，串扰为-14.69dB。该方案虽然工艺简单，只需要一次光刻，但串扰、损耗和尺寸仍然较大；（3）建立了基于倒锥形结构垂直耦合器的桥式波导交叉单元，桥式结构的突出优点是能够从原理上解决串扰的问题。仿真结果显示其损耗为0.035dB，串扰为-43.2dB，尺寸为71.5m1m；该方案达到了低交叉损耗、低串扰的目标，但是其长度至少需要70m，对于高集成度芯片不具备实用性；（4）针对桥式结构长度过大的缺点，作者提出了基于中间层和隔离层的桥式波导交叉方案来降低总长。在尺寸为10.4m0.5m的情况下损耗为0.24dB，串扰为-40.5dB，。该方案所需长度为10m，同时也保持了桥式结构结构几乎无串扰的特性，是对基于桥式结构的波导交叉单元结构有意义探索。
[Abstract]:With the development of modern photonic technology, the integration of devices, the density, function and performance of on-chip devices are becoming more and more important. This results in a great increase in the number of intersections between optical waveguides on a single chip. At the same time, as a hot material for optical integration research, the SOII-Silicon on Isolator material has the advantages of good light conductivity, strong limiting effect on light and full compatibility with the standard CMOS process, etc. However, the large core / cladding refractive index difference of SOI makes the space angle of the guide mode very large. The loss and crosstalk of SOI optical waveguide are 1 ~ 1.5 dB and -10 ~ (-15) dB, respectively. A large number of crossover losses and crosstalk will be unacceptable for a single chip. This paper attempts to design a compact, low crossover loss, low crosstalk SOI optical waveguide crossover scheme, and can be compatible with semiconductor technology. The main contents of this thesis are as follows:. (1) A lossless positive cone taper and an inverted conical inverse taper are constructed. The variation of mode field width and effective refractive index in the inverted cone structure is analyzed. (2) the waveguide crossover unit based on multi-mode interference structure is simulated by Comsol. The loss is 0.22 dB and crosstalk is -14.69 dB when the size is 13m13m. Although the process is simple and only one lithography is required, the crosstalk, loss and size are still large. A bridge waveguide crossover element based on inverted conical vertical coupler is established. The outstanding advantage of the bridge structure is that it can solve the crosstalk problem in principle. The simulation results show that the crosstalk loss is 0.035 dB, the crosstalk is -43.2 dB, and the size is 71.5 m1.This scheme achieves the goal of low crossover loss and low crosstalk. However, the length of the chip needs at least 70m, which is not practical for high integration chip. (4) in view of the drawback of the excessive length of the bridge structure, A bridge waveguide crossing scheme based on intermediate layer and isolation layer is proposed to reduce the total length. When the size is 10.4m0.5m, the loss is 0.24dBand the crosstalk is -40.5dB0.The length of the scheme is 10m, and the structure of bridge structure is almost free of crosstalk. It is a meaningful exploration of waveguide cross element structure based on bridge structure.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN814

【相似文献】