Robust generation of intrinsic C points with magneto-optical bound states in the continuum
C points, circular polarization in momentum space, play crucial roles in chiral wave manipulations. However, conventional approaches of achieving intrinsic C points using photonic crystals with broken symmetries suffer from a low Q factor and high sensitivity to structural geometry, rendering them fragile and susceptible to perturbations and disorders. We report magneto-optical (MO) bound states in the continuum (BICs) with a symmetry-preserved planar photonic crystal. We achieve intrinsic C points at Γ point that are robust against variation in both structural geometry and external magnetic field. MO coupling between two modes induces Zeeman splitting, leading to MO BICs and quasi-BICs with circular eigenstates for high-Q chiral responses. Furthermore, switchable C point handedness and circular dichroism are enabled by reversing the magnetic field. These findings unveil BICs and quasi-BICs with circular eigenstates and on-demand control of C points, paving the way for advanced chiral wave manipulation with enhanced light-matter interaction.
2-s2.0-85209696062
39546605
Tsinghua University
École Polytechnique Fédérale de Lausanne
Tsinghua University
Tsinghua University
Tsinghua University
Tongji University
Tsinghua University
Colorado School of Mines
Tsinghua University
2024-11-15
10
46
eads0157
REVIEWED
EPFL
| Funder | Funding(s) | Grant Number | Grant URL |
Shanghai Pilot Program for Basic Research | 62205246 | ||
Shenzhen Science and technology innovation commission | JCYJ20230807111706014,JcYJ20230807111706014 | ||
National Natural Science Foundation of china | 12204264,12474388 | ||
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