Year: 2025
Type: article
Abstract: Radiation asymmetry (RA) characterizes resonant modes in photonic structures that lack up-down mirror symmetry. In this paper, we introduce a novel RA pseudo-polarization vector that enables a topological analysis of RAs, providing a new method to characterize polarization singularities and their associated topological charges within parameter space. This approach is further strengthened by representing RA as a complex number mapped onto the unit disk of the complex plane, offering a comprehensive framework to evaluate a structure’s control over RA and allowing for precise optimization of target RAs. Using the proposed concept and method, we analyze RAs in trilayer metagratings. Numerical results show that a wide range of pseudo-polarization states can be achieved without breaking the structure’s inversion symmetry. The trilayer metagrating supports RAs with arbitrary directionality, and the phase difference can be continuously modulated from − 2 π / 3 to 2 π / 3 , allowing for precise control over both the directionality and phase difference.
Source: Journal of Optics
Authors: Xun Lu, Lijun Yuan
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
Awards: G2796437284, G5743440164, G5793339358
OpenAlex ID: W4408434414