A novel compact electromagnetic diode based on Fano resonance is reported, realized by combining a ­defective photonic crystal with a varactor-loaded split ring resonator. One-way response is achieved in a microwave waveguide system, attributed to the sharp asymmetric Fano lineshape, the strong nonlinearity enhancement, and the pronounced nonreciprocal field localization. A low threshold intensity of −1.6 dBm, a high transmission contrast up to 17.1 dB, and a maximal transmission over −16 dB are achieved within a subwavelength volume. Compared with conventional electromagnetic diode designs based on ­defective photonic crystals, the presence of interaction between cavity and resonator provides more flexibility in tuning the transmission properties. The findings may be beneficial for designing nonreciprocal integrated photonic devices in practical application.

中文翻译：

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非对称侧耦合腔谐振器系统中的电磁二极管作用

报道了一种基于 Fano 谐振的新型紧凑型电磁二极管，通过将有缺陷的光子晶体与变容二极管开口环谐振器相结合来实现。在微波波导系统中实现了单向响应，这归因于尖锐的非对称 Fano 线形、强非线性增强和明显的非互易场定位。在亚波长范围内实现了 -1.6 dBm 的低阈值强度、高达 17.1 dB 的高传输对比度和超过 -16 dB 的最大传输。与基于缺陷光子晶体的传统电磁二极管设计相比，腔和谐振器之间相互作用的存在为调整传输特性提供了更大的灵活性。