Experimental Realization of Sensitivity Enhancement and Suppression with Exceptional Surfaces
Journal article, 2021
By preparing a sensor system around isolated exceptional points, one can obtain a great enhancement of the sensitivity benefiting from the non-Hermiticity. However, this comes at the cost of reduction of the flexibility of the system, which is critical for practical applications. By generalizing the exceptional points to exceptional surfaces, it has been theoretically proposed recently that enhanced sensitivity and flexibility can be combined. Here, an exceptional surface is experimentally demonstrated in a non-Hermitian photonic sensing system, which is composed of a whispering-gallery-mode microresonator and two nanofiber waveguides, resulting in a unidirectional coupling between two degenerate counter-propagating modes with an external optical isolator. The system is simple, robust, and can be easily operated around an exceptional surface. On the one hand, sensitivity enhancement is observed by monitoring the resonant frequency splitting caused by small perturbations. This demonstration of exceptional-surface-enhanced sensitivity paves the way for practical non-Hermitian sensing applications. On the other hand, the suppression of frequency splitting around the exceptional surface is also shown for the first time.
whispering gallery mode microresonators
exceptional surfaces
sensitivity enhancement
Author
Guo Qing Qin
Tsinghua University
Beijing Institute of Radio Measurement
Ran Ran Xie
Tsinghua University
Hao Zhang
Tsinghua University
Yun Qi Hu
Tsinghua University
Min Wang
Tsinghua University
Gui Qin Li
Tsinghua University
Haitan Xu
Southern University of Science and Technology
Fuchuan Lei
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
Dong Ruan
Tsinghua University
Gui Lu Long
National Climate Center Beijing
Frontier Science Center for Quantum Information
Beijing Academy of Quantum Information Sciences
Tsinghua University
Laser and Photonics Reviews
1863-8880 (ISSN) 1863-8899 (eISSN)
Vol. 15 5 2000569Subject Categories
Atom and Molecular Physics and Optics
Other Physics Topics
Other Electrical Engineering, Electronic Engineering, Information Engineering
DOI
10.1002/lpor.202000569