Goos-Hänchen shifts of a bilayer metagrating with unidirectional guide resonance
Phys. Rev. B 113, 155404 – Published 3 April, 2026
DOI: https://doi.org/10.1103/zhtf-trz5
Abstract
Bilayer metagratings with asymmetric structural parameters could host unidirectional guide resonances. The distribution of unidirectional guide resonances in the space of structural parameters and synthetic parameters is identified. As the incident optical beam is resonant with the unidirectional guide resonance, the Goos-Hänchen shifts of the scattered beams exhibit two anomalous behaviors: The resonant peak of the Goos-Hänchen shift is accompanied by constant transmittance and reflectance, and the magnitude of the Goos-Hänchen shift is not always proportional to the quality factor of the unidirectional guide resonance. The temporal coupled mode theory analysis reveals that the first anomalous behavior is due to interference between direct scattering and radiation from the unidirectional guide resonance; the Goos-Hänchen shifts are proportional to the group velocity as well as the quality factor of the unidirectional guide resonance. Numerical simulations of the incidence of the Gaussian beam with finite beamwidth provide intuitive visualization of the Goos-Hänchen shift.
Physics Subject Headings (PhySH)
Corrections
15 May, 2026
Correction: The omission of the Acknowledgment section has been rectified. The term “Goos-Hänchen” was displayed incorrectly in the title, abstract, and the second sentence of Sec. I and has been fixed.
