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Non-orthogonal cavity modes near exceptional points in the far field.
- Source :
-
Communications Physics . 1/5/2024, Vol. 7 Issue 1, p1-8. 8p. - Publication Year :
- 2024
-
Abstract
- Non-orthogonal eigenstates are a fundamental feature of non-Hermitian systems and are accompanied by the emergence of nontrivial features. However, the platforms to explore non-Hermitian mode couplings mainly measure near-field effects, and the far-field behaviours remain mostly unexplored. Here, we study how a microcavity with non-Hermitian mode coupling exhibits eigenstate non-orthogonality by investigating the spatial field and the far-field polarization of cavity modes. The non-Hermiticity arises from asymmetric backscattering, which is controlled by integrating two scatterers of different size and location into a microdisk. We observe that the spatial field overlap of two modes increases abruptly to its maximum value, whilst different far-field elliptical polarizations of two modes coalesce when approaching an exceptional point. We demonstrate such features experimentally by measuring the far-field polarization from the fabricated microdisks. Our work reveals the non-orthogonality in the far-field degree of freedom, and the integrability of the microdisks paves a way to integrate more non-Hermitian optical properties into nanophotonic systems. Whispering gallery mode microcavities with asymmetric backscattering provide a platform to characterise non-orthogonal Hermitian features, but the majority of the studies focus on near-field measurements. The authors realize a non-Hermitian platform and characterise its far-field features in terms of polarization via confocal micro-photoluminescence. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 23993650
- Volume :
- 7
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Communications Physics
- Publication Type :
- Academic Journal
- Accession number :
- 174643906
- Full Text :
- https://doi.org/10.1038/s42005-023-01508-2