Designing plasmonic exceptional points by transformation optics

Exceptional points (EPs) have been shown to be useful in bringing about sensitive optical properties based on non-Hermitian physics. For example, they have been applied in plasmonics to realize nano-sensing with extreme sensitivity. While the exceptional points are conventionally constructed by considering parity-time symmetric or anti-parity-time symmetric media, we theoretically demonstrate the possibility of generating a series of non-Hermitian systems by transforming a seed system with conventional parity-time symmetry within the transformation optics framework. The transformed systems do not possess PT-symmetry with a conventional parity operator after a spatial operation, i.e. hidden from conventional sense, but are equipped with exceptional points and phase transitions, hinting an alternative method to design non-Hermitian plasmonic systems with sensitive spectra or eigenmodes. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

Exceptional points (EPs) are a useful tool in achieving sensitive optical properties based on non-Hermitian physics, such as in plasmonics for nano-sensing. By transforming a seed system with conventional parity-time symmetry, a series of non-Hermitian systems can be generated with exceptional points and phase transitions, providing an alternative approach for designing sensitive optical systems.