光学学报, 2017, 37 (3): 0323002, 网络出版: 2017-03-08
打破光子晶体非线性Fano腔结构对称性实现单向传输
Achieving Nonreciprocal Transmission by Breaking Symmetry of Nonlinear Fano Cavity Structure in Photonic Crystals
光学器件 光子晶体 Fano腔 单向传输 全光二极管 optical devices photonic crystal Fano cavity nonreciprocal transmission all-optical diode
摘要
设计了一种基于二维光子晶体波导旁侧Fano微腔的全光二极管结构, 实现光的单向传输。其关键技术是在光子晶体波导中采用简单反射层打破Fano微腔结构上的空间对称性, 使得反射层两侧波导与微腔耦合效率不对称。两侧波导入射光激发微腔非线性克尔材料所需的光强阈值不同, 从而实现单向导通功能。通过有限时域差分(FDTD)方法对其传输特性和性能进行了数值仿真和分析, 研究发现:该结构在较低的光强阈值下可以实现正向导通、反向截止的全光二极管效果; 该结构具有超快的响应时间, 达到皮秒量级; 该结构具有较高的最大透射率(达到90%)和较高的正反透射比。基于光子晶体结构的设计使得该器件可以具有很好的工作波长可调特性, 并易于在目前半导体工艺基础上进行制作以及与其他器件集成。
Abstract
An all-optical diode structure based on Fano micro-cavity at the side of 2D photonic crystal waveguide is designed to realize the nonreciprocal transmission of light. The key technique is to break the spatial symmetry of Fano micro-cavity structure by using a simple reflecting layer in the photonic crystal (PC) waveguide, so that the coupling efficiency of waveguide on both sides of the reflective layer and micro-cavity is asymmetric. Since the thresholds of incident light intensity required for the nonlinear Kerr material to excite the micro-cavity on both sides of the waveguide are different, the function of one-way conduction is achieved. The transmission properties and performance are numerically simulated and investigated by finite-difference time-domain (FDTD) method. The results show that forward transmission and backward cut-off all-optical diode effect can be achieved in this structure with low light intensity threshold. The structure has ultra-fast response time, which can reach the order of picoseconds. It also has high maximum transmittance (about 90%), and high positive and negative transmittance. The design based on photonic crystal structure enables the device to have good work wavelength tunable characteristics, which makes it easy to produce and integrate with other devices on the basis of current semiconductor technology.
胡金凤, 刘彬, 梁红勤, 刘娟. 打破光子晶体非线性Fano腔结构对称性实现单向传输[J]. 光学学报, 2017, 37(3): 0323002. Hu Jinfeng, Liu Bin, Liang Hongqin, Liu Juan. Achieving Nonreciprocal Transmission by Breaking Symmetry of Nonlinear Fano Cavity Structure in Photonic Crystals[J]. Acta Optica Sinica, 2017, 37(3): 0323002.