【作者】 蒋红；

【导师】 郜定山；

【作者基本信息】 华中科技大学 ， 光电信息工程， 2011， 硕士

【摘要】 近年来,硅基光互连乃至光计算成为世界科技研究热点,尤其是基于绝缘体上硅(SOI)晶片的各种有源、无源光电子器件的研究更是方兴未艾。目前,已有大量无源光子器件如光波导、调制器、滤波器、波分复用器等在SOI结构上实现。然而,基于硅基的片上光源研制仍困难重重,片外光源成为目前的主要选择。外部光源与SOI光波导器件的高效耦合成为急需解决的关键问题。垂直光栅耦合器具有耦合效率高、耦合对准允差性好等突出优点。本文在武汉光电国家实验室(筹)创新基金的资助下,主要研究了硅基二元闪耀光栅垂直耦合器的设计及制备,主要工作如下:(1)基于严格耦合波分析(rigorous coupled-wave analysis, RCWA),对传统的均匀光栅耦合器模型进行改进,推导了二元闪耀光栅耦合器的耦合效率,得到了二元闪耀光栅衍射效率随器件结构各参数变化的关系曲线。(2)建立了基于SOI结构的二元闪耀光栅耦合器的理论设计模型,该耦合器与常规的均匀光栅耦合器相比,实现了在接近垂直耦合的情况下,获得了高的耦合效率及较大的带宽,在浅刻蚀的情况下,耦合效率可以达到60%,而不用在衬底制作任何辅助反射镜结构,制作工艺更简便。(3)在一维二元闪耀光栅设计基础上,我们提出了二维闪耀光栅耦合器的理论设计模型,工艺上可以通过一次性刻蚀同时制作出光栅耦合器和波导结构,无需套刻。其耦合效率和1 dB带宽分别达到60.2%和100 nm。(4)对硅基二元闪耀光栅垂直耦合器制作工艺进行了探索,初步制作了器件样品。更多还原

【Abstract】 Recently, silicon-based optical interconnection as well as optical computing becomes the research hotspots in the world, especially for the research on both passive and active optoelectronic devices which are based on SOI wafer. And now, a lot of passive optoelectronic devices have been produced on SOI wafer, such as optical waveguides, modulators, filters, WDM devices, etc. However, silicon-based on-chip light source is very difficult to be realized, so the external light source is still the main choice. The high coupling efficiency between external source and SOI waveguide becomes the key issue. Vertical grating couplers have the advantage of high coupling efficiency and good alignment tolerance.Supported by the“Creative Foundation of Wuhan National Laboratory for Opto -electronics”, the design and fabrication of binary blazed vertical grating coupler has been studied in this thesis. The main works are listed as follows:(1) Based on the rigorous coupled-wave analysis, the coupling efficiencies of ordinary grating coupler and binary blazed grating coupler have been deduced and compared.(2) The theoretical design of binary blazed grating coupler based on SOI have been introduced in detail. Simulations demonstrate it has higher coupling efficiency and larger bandwidth under nearly vertical coupling. When the blazed grating is shallowly etched, the coupling efficiency can reach as high as 60% without introducing any extra back reflection mirror in the substrate.(3) Based on the grating diffraction and effective medium approximation, a novel blazed grating coupler consisting of two dimensional (2D) fully-etched rectangular air holes is proposed to enhance the coupling efficiency and bandwidth for vertical coupling between fiber and silicon-on-insulator (SOI) waveguide. 2D finite-difference time-domain (FDTD) simulations demonstrate that the coupling efficiency at 1550 nm wavelength is 60.2%, and the 1dB bandwidth is 100 nm. The proposed grating coupler along with the waveguide can be fabricated by only one step of lithography and etching processes, without any overlay processes. (4) The fabrication process of binary blazed vertical grating coupler have been studied, and the initial device sample has been produced.更多还原