基于非对称微波光子晶体的电磁二极管

Electromagnetic diode based on asymmetric microwave photonic crystal

通过引入具有类电磁诱导透明效应的超材料,非对称光子晶体谐振腔的透射特性得到了极大的优化,包括透射峰的品质因子和谐振腔模所对应的电磁场强度.品质因子的提高与非对称场强局域的增强有利于高性能电磁二极管的实现.我们在引入非线性材料的微带波导系统中验证了该方案.实验结果显示,此二极管在1.329 GHz的工作频率下可产生高达19.7 dB的透射对比度,同时输入功率强度仅为7 dBm.此外,我们提出的方案并没有大幅增加器件体积和剧烈降低信号透过率.这些特性的亚波长尺度实现将有益于集成光学回路的小型化.

A subwavelength electromagnetic diode scheme in a microwave waveguide system is proposed by using an asymmetric photonic crystal(PC)cavity side-coupled with electromagnetically induced transparency like(EIT-like)metamaterials.It is found that the composite PC-EIT configuration can generate tenfold Q-factor enlargement,accompanied with enhanced nonreciprocal electromagnetic localization simultaneously.Further study of the measured one-way response exhibits excellent electromagnetic diode performance including 19.7 dB transmission contrast and 7 dBm operating power at a working frequency of 1.329 GHz.We emphasize that such high-contrast transmission and low-threshold diode actions are not at costs of greatly increasing volume and drastically reducing transmission.Our findings may benefit the design of compact nonreciprocal devices in the integrated optical nanocircuits.