Ding Wei, Liu Rong-Juan, Li Zhi-Yuan
Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190, China.
Opt Express. 2012 Dec 17;20(27):28641-54. doi: 10.1364/OE.20.028641.
Interferometric behaviours in radiation generation process of a one-dimensional photonic-crystal (PhC) reflector are investigated on a silica waveguide. An analytical model, which can calculate total radiation losses, is presented after analysing eigen-mode properties and radiation pattern characteristics. Our model takes into account the interference of component radiated waves generated at interfaces between different waveguide sections and is verified by comparing with numerical simulations of periodic and non-periodic one-dimensional PhC reflectors. Its capability to quickly find minimum-radiation tapering geometries helps circumvent time-consuming numerical simulations. Our model negates the conventional knowledge that a gradually tapered transition from uniform waveguide to PhC waveguide yields lower radiation loss. In one example, the gradually tapered transition produces 2.3dB more radiation than the optimum geometry.
在二氧化硅波导上研究了一维光子晶体（PhC）反射器辐射产生过程中的干涉行为。在分析本征模特性和辐射方向图特征后，提出了一个能够计算总辐射损耗的解析模型。我们的模型考虑了在不同波导段之间的界面处产生的分量辐射波的干涉，并通过与周期性和非周期性一维PhC反射器的数值模拟进行比较来验证。它能够快速找到最小辐射渐变几何结构，有助于避免耗时的数值模拟。我们的模型否定了传统观念，即从均匀波导到PhC波导的逐渐渐变过渡会产生更低的辐射损耗。在一个例子中，逐渐渐变过渡产生的辐射比最佳几何结构多2.3dB。
