[10a-B11-1~12] 3.10 Photonic structures and phenomena

12:00 PM - 12:15 PM JST(3:00 AM - 3:15 AM UTC)

[10a-B11-12] BIC splitting and chiral singularity control via symmetry breaking in non-Hermitian photonic crystals

〇Tooi Suzuki^1,2, Takumi Harada^1,2, Taiki Yoda¹, Takahiro Uemura², Masaaki Ono^2,3, Eiichi Kuramochi^2,3, Yuto Moritake⁴, Masaya Notomi^1,2,3 (1.Science Tokyo, 2.NTT BRL, 3.NTT Nanophotonics Center, 4.IIS, University of Tokyo)

Keywords:

Photonic crystal,Chirality,Symmetry control

We show that, by applying a non-Hermitian perturbation that breaks the mirror symmetry while preserving the C2T symmetry to a photonic crystal hosting an at-Γ BIC, the BIC moves in k-space and becomes an off-Γ BIC. Furthermore, we reveal that breaking the remaining mirror symmetry splits the off-Γ BIC into two C-points (CPs), enabling the generation of a CP at the Γ point. We show that these processes cannot be described by the BIC band alone, but are instead explained by a four-band k·p perturbation model.