High efficiency all-optical plasmonic diode based on a nonlinear side-coupled waveguide-cavity structure with broken symmetry
High efficiency all-optical plasmonic diode based on a nonlinear side-coupled waveguide-cavity structure with broken symmetry
复制标题
基于对称性破缺非线性侧耦合波导腔结构的高效全光等离子体二极管
DOI：
10.1016/j.optcom.2017.12.081
复制
发表时间：
2018
影响因子：
2.4
通讯作者：
He Xing Dao
中科院分区：
文献类型：
--
作者：
Liang Hong Qin;Liu Bin;Hu Jin Feng;He Xing Dao
提出了一种基于非线性Fano结构的全光等离子体二极管，它由金属-绝缘体-金属波导和短截线腔耦合而成。所采用的关键技术是通过在波导中添加简单的反射层来打破结构的空间对称性。该结构的空间不对称性引起Fano腔和反射层两侧波导之间的耦合效率的非互易性，导致非互易非线性响应。采用非线性时域有限差分法对该结构的传输特性和动态响应进行了数值模拟和研究。在所提出的结构中，高效率的非互易传输可以实现低功率阈值和超快的响应时间（亚皮秒级）。还可以获得89.3%的高最大透射率和99.6%的超高透射对比度。该器件可以通过改变短截线腔的长度来灵活地调整工作波段。
An all-optical plasmonic diode, comprising a metal–insulator–metal waveguide coupled with a stub cavity, is proposed based on a nonlinear Fano structure. The key technique used is to break structural spatial symmetry by a simple reflector layer in the waveguide. The spatial asymmetry of the structure gives rise to the nonreciprocity of coupling efficiencies between the Fano cavity and waveguides on both sides of the reflector layer, leading to a nonreciprocal nonlinear response. Transmission properties and dynamic responses are numerically simulated and investigated by the nonlinear finite-difference time-domain method. In the proposed structure, high-efficiency nonreciprocal transmission can be achieved with a low power threshold and an ultrafast response time (subpicosecond level). A high maximum transmittance of 89.3% and an ultra-high transmission contrast ratio of 99.6% can also be obtained. The device can be flexibly adjusted for working wavebands by altering the stub cavity length.