Illegal food chemicals sensing with photonic crystal fiber sensor in the terahertz spectrum

The method by which a photonic crystal is manufactured fiber is detailed throughout the subsequent undertaking, containing a hexahedron core and hazardous dietary additives using a hexagonal cladding. Saccharine, sorbitol, and butyl acetate are used as analytes for sensing purposes. The sensor contains five tiers of circular ventilation holes within the hexagonal framework, as well as two tiers of hexahedron circles in the central area. FEM (Finite Element Method) is implemented in the sensor design of COMSOL software version 4.2. We noticed the response of the PCF sensor to the specific substances. We examined key optical metrics encompassing specifications including V-parameter, Relational sensitivity, effective refractive index, and power fraction to assess the suitability of the sensor for precisely and effectively detecting various food additives. The revised model attains sensitivity values of 90.10%, 91.30%, and 86.60%, respectively, at a frequency of 1 THz, the identification of saccharine (1.550 in the index of refraction), sorbitol (1.375 in the index of refraction), and butyl acetate (1.394 in the index of refraction) is performed. Furthermore, the compositions of saccharine (1.550 in the index of refraction), sorbitol (1.375 in the index of refraction), and butyl acetate (1.394 in the index of refraction) demonstrate losses from confinement of 6.15 × 10⁻⁸ dB/m, 7.25 × 10⁻⁸ dB/m, and 6.35 × 10⁻⁸ dB/m, which are comparatively minimal, and 0.0235 cm⁻¹ is an insignificant effective material loss. These structures are studied at the terahertz frequency spectrum. Owing to its superior wave-guiding properties, this proposed sensor can be used for polarization-preserving terahertz wave applications and detecting dangerous food additives. Besides, because of simple fabrication, high sensitivity, and low confinement loss, we strongly believe this optimized geometrical structure will contribute to real-life applications that lead to safer food and support a circular economy in developing countries.