Terahertz metasensor with pseudo parity time symmetry for oral cancer diagnostics

Abstract

This study presents the design and theoretical analysis of a pseudo parity-time symmetric photonic crystal biosensor for early oral cancer detection. Using the transfer matrix method, we numerically investigated the resonant transmission properties of a 1D photonic crystal structure with a central defect layer (D = 50 μm) containing healthy and cancer oral cells. The proposed [Formula: see text] configuration exhibits exceptional sensitivity, quantified by two key metrics: a spectral sensitivity of 118 GHz/RIU and an extraordinary transmittance sensitivity of [Formula: see text] These results demonstrate significant improvements over conventional photonic biosensors, enabled by the PT-symmetric design's ability to operate near an exceptional point. The optimized structure achieves ultra-sharp resonances ([Formula: see text] THz FWHM) with remarkable field enhancement, making it particularly suitable for detecting minute refractive index changes associated with malignant transformations. Our findings establish a foundation for developing high-performance, label-free diagnostic tools for early-stage oral cancer detection.

Keywords: Oral cancer; Photonic crystal; Terahertz sensor, parity time symmetry.

Fig. 1

Geometry of as oral cancer detector.

Fig. 2

Experimental and fitted (a) real RI and (b) absorption of normal and cancered oral samples at room temperatures.

Fig. 3

Transmittance of proposed oral cancer detector without defect, with normal cells, and with cancered cells at room temperature, , initial of zerro degree, and of 50 .

Fig. 4

Geometry of as oral cancer detector according to PT symmetry.

Fig. 5

Transmittance of proposed oral cancer detector with normal cells at room temperature, N = 4, initial of zerro degree, and of 50 for (a) , (b) , (c) , (d) , (e) , (f) , (g) , (h) , (i) , (j) , (k) , (l) , (m) , (n) , and (o) .

Fig. 6

FWHM and Transmittance of proposed detector with healthy cells versus Q at room temperature, , initial of zerro degree, and of 50 .

Fig. 7

Transmittance of proposed oral cancer detector with cancer cells at room temperature, , initial of zerro degree, and of 50 for (a) , (b) , (c) , (d) , (e) , (f) , (g) , (h) , (i) , (j) , (k) , (l) , (m) , (n) , and (o) .

Fig. 8

FWHM and Transmittance of proposed detector with cancer cells versus at room temperature, , initial of zerro degree, and of 50 .

Fig. 9

Transmittance of proposed oral cancer detector with oral healthy and cancer cells at room temperature, , initial of zerro degree, of 50 , and .