We study the breaking of reciprocity in non-Hermitian coupled photonic waveguides by the simultaneous action of the nonlinear effect of saturable absorption and the presence of exceptional points. The nonlinear response of such a system is studied in depth, giving physical insight into the operational principles and fundamental limitations while producing analytical and semianalytical results for the transmission and nonreciprocal intensity range. We numerically validate the theoretical results and assess important performance metrics for the nonreciprocal operation of such a device. This class of passive nonresonant devices can offer broadband on-chip nonreciprocal operation, with significant potential for high-speed applications.

中文翻译：

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在具有饱和吸收的非Hermitian光子耦合器中打破互易性

我们通过饱和吸收的非线性效应和特殊点的存在的同时作用，研究了非赫米特耦合光子波导中互易性的破坏。对该系统的非线性响应进行了深入研究，从物理上深入了解了工作原理和基本局限性，同时针对透射和不可逆强度范围生成了分析和半分析结果。我们用数值方法验证了理论结果，并评估了这种设备不可逆操作的重要性能指标。这类无源非谐振设备可以提供宽带片上不可逆操作，在高速应用中具有巨大潜力。