近红外波段硅基二维平板光子晶体单向光学器件的理论和实验研究

With the development of micro-nanofabrication technology, the near-infrared two-dimensional photonic crystal slab becomes an important platform to achieve all-optical integration. However, the development of optical diode and optoisolator is currently a recognized problem in the micro-nano integrated photonics field. In this project, various kinds of the two-dimensional photonic crystal slab unidirectional devices are studied both theoretically and experimentally on the basis of our perious achievements, including the unidirectional propagating and splitting devices based on the difference of the photonic crystal's directional bandgaps, the unidirectional propagating waveguides based on the mode conversion between adjacent waveguides, and the unidirectional wavelength filters based on the difference of the mode coupling strength. In theory, we plan to study the different kinds of silicon-based air-hole and metallic two dimensional photonic crystal slab structures by using the three-dimensional finite-difference time-domain method and the plane wave expansion method, and acquire the optimized parameters of the unidirectional optical devices through designing the photonic crystals' whole structures. In experiment, we plan to use the electron beam lithography technique, the inductively coupled plasma etching technique and the magnetron sputtering technique to fabricate the device samples with the optimized structures, and the optical transmission characters through the samples are also measured by the micro-region spectrum measurement system and the near-field scanning optical microscope system. This research project will help promote the specific applications of the unidirectional photonic crystal optical devices in all-optical integrated circuit.

随着微纳米加工技术的发展，近红外波段二维平板光子晶体成为实现全光集成的重要平台，然而光二极管和光隔离器的研制却是当前微纳集成光子学领域的一个公认难题。本项目在前期工作成果的基础上，拟从理论和实验两方面研究不同类型的二维平板光子晶体单向光学器件，主要包括基于光子晶体方向带隙差异的单向传输和分束器件；基于波导间模式转换的单向传输波导；基于缺陷体与相邻波导间模场耦合强度差异的单向滤波器件。理论方面，拟利用三维时域有限差分方法和平面波展开方法研究不同结构的硅基空气孔和金属型二维平板光子晶体，通过整体结构的设计，获得各类单向光学器件的最优化参数。实验方面，拟利用电子束曝光技术、电感耦合等离子体刻蚀技术并结合磁控溅射等技术制备出最优化参数后的单向光学器件样品，然后利用微区光谱测量系统和近场扫描光学显微镜系统测量其光学传输特性。本项目的研究成果将有助于推动光子晶体单向光学器件在全光集成回路中的具体应用。

随着微纳米加工技术的发展，近红外波段硅基二维平板光子晶体成为实现全光集成的重要平台，然而光二极管和光隔离器的研制却是当前微纳集成光子学领域的一个难题。本项目从理论和实验两方面研究了不同类型的二维平板光子晶体单向光学器件，主要包括基于光子晶体方向带隙差异的单向传输和分束器件；基于波导间模式转换的单向传输波导；基于缺陷体与相邻波导间模场耦合强度差异的单向滤波器件。本项目根据预定的研究内容和研究目标，在二维光子晶体单向分束器、近红外波段二维平板光子晶体单向分束器、光子晶体耦合腔波导、光子晶体多通道滤波器、光子晶体传感器等方面取得了较好的成果。通过设计两种不同半径的二维正方晶格光子晶体，并且在交界面处将不同半径介质柱交错排列，基于光子晶体方向带隙差异和相应频率区域的自准直效应，实现了在不同频率范围内的单向分束特性，并且在这两个频率范围内正向光传输方向是相反的；在此基础上通过优化设计交界面处介质柱的排列方式，使得正向传输时的透过率得到了进一步的提升; 利用电子束曝光结合电感耦合等离子体刻蚀方法实验制备了近红外波段的二维平板硅基空气孔型单向分束器，通过改变出射端面处空气孔排列的周期性，利用近场扫描光学显微镜实验观察到了入射光束经过结构后的两分束、三分束和四分束现象；基于二维三角晶格光子晶体，通过改变了耦合区介质柱形状以及出射通道的位置，最终较好地实现了利用同一结构，在三个出射波导位置分别以三均分、二均分、单一通道三种能量分配模式输出一定频率范围光波的功能。在基金委的支持下，本项目组成员在Journal of Physics D: Applied Physics, Optics Express, Optics Communications, Solid State Communications等学术期刊和学术会议上共发表论文28篇，申请发明专利1项。