摘要：The evolution in momentum space of bound states in the continuum (BICs) and circularly polarized states (CPSs) - as far-field polarization singularities - can be observed by controlling the geometric parameters of photonic crystals. This offers significant potential in optics and photonics. Here, we reveal that in complex lattices far-field polarization singularities can be flexibly manipulated while preserving structural symmetry. A change in topological charge for the at-Gamma BIC can generate new BICs or CPSs. At an off-Gamma point, a BIC can spawn from the collision of two CPSs. As the thickness of the structure increases, this BIC will meet the at-Gamma BIC. The merging of BICs can induce topological charge transition and yield a large wavevector space around the Gamma point with ultra-high quality (Q) factors. Our findings provide a novel degree of freedom for manipulating polarization singularities, which holds great promise in radiation modulation and singular optics.

关键字：bound states in the continuum; circularly polarized states; topological charge; far-field polarization; photonic crystals; 73.20.At; 78.67.Pt

ISSN号：1674-1056

卷、期、页：卷: 34期: 3

发表日期：2025-03-01

期刊分区（SCI为中科院分区）：四区

收录情况：SCI（科学引文索引印刷版）,EI（工程索引）,SCIE（科学引文索引网络版）

发表期刊名称：CHINESE PHYSICS B

参与作者：Wang, Mengyao,Shi, Tian,Liu, Peng,Li, Liangsheng,Zheng, Ning

第一作者：宁鲁慧

论文类型：期刊论文

论文概要：Wang, Mengyao,Shi, Tian,宁鲁慧,Liu, Peng,Li, Liangsheng,Zheng, Ning，Merging and separation of polarization singularities in complex lattices，CHINESE PHYSICS B，2025，卷: 34期: 3

论文题目：Merging and separation of polarization singularities in complex lattices