Frontiers of Optoelectronics, Volume. 14, Issue 2, 211(2021)
PTX-symmetric metasurfaces for sensing applications
In this paper, we introduce an ultra-sensitive optical sensing platform based on the parity-time-reciprocal scaling (PTX)-symmetric non-Hermitian metasurfaces, which leverage exotic singularities, such as the exceptional point (EP) and the coherent perfect absorber-laser (CPAL) point, to significantly enhance the sensitivity and detectability of photonic sensors. We theoretically studied scattering properties and physical limitations of the PTXsymmetric metasurface sensing systems with an asymmetric, unbalanced gain-loss profile. The PTX-symmetric metasurfaces can exhibit similar scattering properties as their PT-symmetric counterparts at singular points, while achieving a higher sensitivity and a larger modulation depth, possible with the reciprocal-scaling factor (i.e., X transformation). Specifically, with the optimal reciprocalscaling factor or near-zero phase offset, the proposed PTXsymmetric metasurface sensors operating around the EP or CPAL point may achieve an over 100 dB modulation depth, thus paving a promising route toward the detection of small-scale perturbations caused by, for example, molecular, gaseous, and biochemical surface adsorbates.
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Zhilu YE, Minye YANG, Liang ZHU, Pai-Yen CHEN. PTX-symmetric metasurfaces for sensing applications[J]. Frontiers of Optoelectronics, 2021, 14(2): 211
Category: RESEARCH ARTICLE
Received: Jan. 13, 2021
Accepted: Feb. 21, 2021
Published Online: Dec. 1, 2021
The Author Email: CHEN Pai-Yen (pychen@uic.edu)