The applicability of resonant waveguide grating (RWG)-based structures as filters to control the spectral response in an optical communication system is investigated. A new physical model for the structure is established on the basis of the Fabry–Pérot (FP) etalon model and coupled leaky mode theory (CLMT). It is found that the flat-top spectral response of the filter is achieved by the combined effect of the guided-mode resonance of an RWG and its Fabry–Pérot resonance (FPR). The bandwidth-tunable spectral response of the filter can be varied according to the change in the eigenvalues of the RWG by changing the structural parameters such as strip width of the grating and incident angle. The flat-top and bandwidth-tunable RWG-based resonant filter is a promising application for high-performance optical communication systems.

中文翻译：

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级联谐振光栅中的可调平顶滤波响应

研究了基于谐振波导光栅（RWG）的结构作为控制光通信系统中光谱响应的滤波器的适用性。在Fabry-Pérot（FP）标准具模型和耦合泄漏模式理论（CLMT）的基础上，建立了该结构的新物理模型。已经发现，滤波器的平顶光谱响应是通过RWG的导模共振及其Fabry-Pérot共振（FPR）的综合作用来实现的。通过改变结构参数，例如光栅的条宽和入射角，可以根据RWG特征值的变化来改变滤波器的带宽可调光谱响应。平顶和带宽可调的基于RWG的谐振滤波器是高性能光通信系统的有前途的应用。