A hybrid structured PCF for fuel adulteration detection in terahertz regime

An elliptical core based hybrid structured photonic crystal fiber (PCF) is proposed and analyzed in order to identify the fuel adulteration level using the terahertz spectrum. The performance of the proposed sensor is assessed by COMSOL software which uses the finite element method as a solver. At 2.8 THz, the proposed sensor shows an extremely high relative sensitivity of 102% with a very small confinement loss of 3.46× 10−11 cm−1 and a high numerical aperture of 0.45. Moreover, the proposed sensor also shows a large effective area of 1.715× 10−8 m2 with a low effective material loss of 0.0105 cm−1 at optimum structural conditions. Except for one elliptical air hole in cladding, the optical sensor contains circular air holes which ensure less complexity during fabrication. The sensor's excellent sensing and guiding properties will make it a competitive candidate in chemical sensing applications.