Work

Dynamical Evolution of BIC‐Fano Dual Modes under Misalignment of Two Waveguide‐Coupled Gratings

Year: 2025

Type: article

Abstract: Applications of bound states in the continuum (BIC) are limited by the challenges of dynamical tuning and coupling to external excitation. In this work, a well‐thought‐out structure model of two gratings coupled by a waveguide is reported. The structure results in unique BIC‐Fano dual modes which undergo an unusual degeneration and inversion by either the tuning of structure parameters or through misalignment of the bilayer gratings, accompanied by the merging and splitting of Quasi(Q)‐BIC and Fano peaks in the transport spectra of the structure. The BIC‐Fano dual mode degeneration leads to the infinite Q factor from BIC and the coupling channel to external excitation from resonance. The results suggest an elegant way for smart engineering of resonances for many applications in optical switching and enhanced light−matter interactions. Especially, the dual‐mode structure gives a highly efficient coupling to a planar waveguide, and is also useful for displacement sensing with an extremely high resolution.

Source: Laser & Photonics Review

DOI: 10.1002/lpor.202500341

Authors: Yun‐tuan Fang, Xielin Qin, Guolong Zhang, Sailing He

Institutions: Jiangsu University, State Key Laboratory of Modern Optical Instruments, Zhejiang University, KTH Royal Institute of Technology

Language: English

Topic: Photonic Crystals and Applications

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,880

Funders: National Natural Science Foundation of China, Zhejiang University, National Key Research and Development Program of China