Short-Wave Infrared Janus Metastructure With Multitasking of Wide-Range Pressure Detection and High-Resolution Biosensing Based on Photonic Spin Hall Effect

The photonic spin Hall effect (PSHE) is an effective measurement approach to characterize changes in pressure and weak refractive index. The metastructure based on a layered structure is equipped with the Janus feature by the asymmetric arrangement of different dielectrics. Electromagnetic waves (EWs) exhibit different electromagnetic characteristics when propagate from opposite directions of the metastructure within the short-wave infrared (SWIR) range. When EWs are incident positively at a frequency
$f$
of 260.87 THz (
$\lambda $
=
$1.15~\mu \text{m}$
), a Janus metastructure (JM) based on PSHE can realize wide-range pressure detection (0–17.2 GPa) with the sensitivity (S) of 1.421°/GPa by using photoelasticity relation of the dielectrics. On the negative scale (EWs incident at
$f$
= 128.39 THz, that is
$\lambda $
=
$2.34~\mu \text{m}$
), stomach cells, liver cells, epidermal cells, and their corresponding cancer cells can be clearly distinguished by the JM refractive index (RI) biosensing with the high resolution up to
$1\times 10^{-6}$
RIU and S =
$5.292\,\, {}\times {}10^{-2}$
m/RIU. The multiscale and multitasking JM proposed not only makes up for the shortcomings of traditional single-scale and single-function sensors, but more importantly, the JM provides a new idea for the development of industrial production, healthcare, and biomedical fields, due to its excellent performance and real-time, label-free and noncontact detection.