Related Experiment Video
Updated: Apr 23, 2026

Stimulated Stokes and Antistokes Raman Scattering in Microspherical Whispering Gallery Mode Resonators
Published on: April 4, 2016
High-Q Chiral Flat-Band Guided Resonances in Nonlocal Metagratings
Baohe Zhang1, Shuangli Li2, Anlong Dong1
1School of Physics, Hefei University of Technology, Hefei, Anhui 230009, China.
None:
Photonic flat bands are central to modern nanophotonics due to their intrinsically large photonic density of states and pronounced slow-light effect. Here, we theoretically propose and experimentally demonstrate a paradigmatic strategy for realizing high-Q, chiral flat-band resonances in a nonlocal metagrating composed of an array of silicon waveguides with bilateral semicircular edge grooves. Driven by tight-binding model in the limit of weak interwaveguide coupling, the flat-band guided modes emerge at a straight silicon waveguide array. By introducing the edge grooves and precisely shifting their lateral positions, the flat-band guided modes evolve into chiral flat-band guided resonances, with ultrahigh Q-factors exceeding 103 over incident angles as wide as ±10° and exhibiting reversible circular dichroism with a sign switch up to ±0.85. Crucially, all experimental results show excellent agreement with those of full-wave simulations. The wide-angle, high-Q chiral flat-band guided resonances will find utility in chiral light sources, polarization-selective detection, and nonlinear frequency conversion.
Related Concept Videos
Chirality
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Chirality in Nature
Chirality at Nitrogen, Phosphorus, and Sulfur
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
Prochirality
Resonance and Hybrid Structures
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
Molecules with Multiple Chiral Centers

