The bimodal resonance phenomena in photonic structure have received particular attention due to their intriguing optical properties and numerous potential applications. In this work, we investigated the mode transformation behaviors of the guided modes in an integrated bimodal resonance structure consisting of a single groove on the surface of an abruptly ended slab waveguide. Numerical simulations demonstrated that the strong mode transformation can occur in the anticrossing region of resonance at the oblique incidence of a transverse electric (TE)-polarized guided mode on the groove. According to the multiple-beam interference model, a theoretical formula was developed to study the resonance and mode transformation behaviors of the guided modes. The results showed that the different anticrossing behaviors of structure are resulting from the constructive and destructive interference of bimodal resonance. The resonance and mode transformation properties of structure can be controlled by adjusting the geometrical parameters of groove. The mode manipulation with high efficiency in the slab waveguide will have many applications in lab-on-a-chip devices, switching and on-chip spectroscopy.

光子结构中的双峰共振现象因其有趣的光学特性和众多潜在应用而受到特别关注。在这项工作中，我们研究了集成双峰共振结构中导模的模式转换行为，该结构由突然终止的平板波导表面上的单个凹槽组成。数值模拟表明，强模式转换可以发生在凹槽上横向电 (TE) 极化导模斜入射的共振反交叉区域中。根据多光束干涉模型，建立了研究导模共振和模态转换行为的理论公式。结果表明，结构的不同抗交叉行为是由双峰共振的相长干涉和相消干涉引起的。通过调整凹槽的几何参数可以控制结构的共振和模态转换特性。板条波导中的高效模式操纵将在芯片实验室设备、开关和芯片光谱学中具有许多应用。