Active dual quasi-BICs in a dielectric metasurface with VO<sub>2</sub> for slow light and optical modulation
We investigate the temperature tunable dual quasi-bound states in the continuum (qBICs) in a silicon/vanadium dioxide (Si/VO<sub>2</sub>) hybrid metasurface with Q-factor being as large as 9.3 × 10<sup>6</sup> and 2.8 × 10<sup>7</sup> by breaking the in-plane C<sub>2</sub> symmetry. The far-field scattering of multipoles and near-field distributions confirm that the toroidal dipole and magnetic quadrupole dominate the dual qBICs resonance. The high performance of slow light with ultralarge group index exceeding 5.6 × 10<sup>5</sup> and the inverse quadratic law between the group index and asymmetric parameter are achieved. By temperature tuning of the VO<sub>2</sub> thin film at the sub-10 K scale, a modulation depth of 90% and the ON/OFF ratio exceeding 12.8 dB are obtained. The proposed temperature tunable dual qBICs have potential applications in the fields of tunable slow light, temperature switches, and sensors.
Authors
- Wei Du (ORCID: https://orcid.org/0000-0001-7890-3099)
- Zhendong Yan (ORCID: https://orcid.org/0000-0002-0005-395X)
- Chaojun Tang (ORCID: https://orcid.org/0000-0003-3435-8177)
- Qianqian Wang (ORCID: https://orcid.org/0000-0002-3022-7930)
- Guo Tian (ORCID: https://orcid.org/0000-0001-7481-0944)
- Ying Zhong
Institutions
- Zhejiang University of Technology (CN)
- Yangzhou University (CN)
Publication Details
- Journal
- Optics Letters
- Published
- 2024-08-22
- DOI
- https://doi.org/10.1364/ol.531338
- Citations
- 21
- Primary Topic
- Metamaterials and Metasurfaces Applications
- Type
- article
- Field-Weighted Citation Impact
- 2.48
Funders
- National Natural Science Foundation of China
- State Key Laboratory of Millimeter Waves