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arXiv · 2310.17184

Multifunctional imaging enabled by optical bound states in the continuum with broken symmetry

Jiale Chen·Zhao-Xian Chen·Jun-Long Kou·Yan-Qing Lu
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Abstract

For photonic crystal slab (PCS) structures, bound states in the continuum (BICs) and circularly polarized states (dubbed C-points) are important topological polarization singularities in momentum-space and have attracted burgeoning attention due to their novel topological and optical properties. In our work, the evolution of polarization singularities from BICs to C-points is achieved by breaking the in-plane C2 symmetry of a PCS structure of a square lattice with C4v symmetry. Correspondingly, a BIC is split into two C-points with opposite chirality, incurring distinct optical transmission responses with the incidence of right or left circular polarization (RCP or LCP). Harnessing such chirality selectivity of the C-points, we propose a multifunctional imaging system by integrating the designed PCS into a conventional 4-f imaging system, to realize both the edge imaging and conventional bright-field imaging, determined by the circular polarization state of the light source. In addition to multifunctional imaging, our system also provides a vivid picture about the evolution of the PCS platforms' singularities.

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Jiale Chen, Zhao-Xian Chen, Jun-Long Kou, Yan-Qing Lu. 2023-10-26. Multifunctional imaging enabled by optical bound states in the continuum with broken symmetry. https://arxiv.org/abs/2310.17184

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