Design of a novel photonic crystal fiber and numerical analysis of sensitivity for the detection of illegal drugs in terahertz regime

In this study, a novel photonic crystal fiber (PCF) based drug sensor has been introduced. The core and cladding area of the hexagonal fiber structure (H-PCF) has round air holes. We examined the model in the THz regime using the FEM and the COMSOL Multiphysics Software platform. With this updated model, the sensitivity to detect amphetamine (n = 1.518), cocaine (n = 1.5022), and ketamine (n = 1.562) at 1 THz is 89.50%, 90.20%, and 85.50% accordingly. Furthermore, the suggested fiber, operating at 1 THz, generated a vast effective area of Ketamine (n = 1.562), cocaine (n = 1.5022), and amphetamine (n = 1.518) of 1.37 × 10−7 m2, 1.40 × 10−7 m2, 1.39 × 10−7 m2 and relatively low confinement loss of 6.40 × 10−8 dB/m, 7.10 × 10−8 dB/m, 6.20 × 10−8 dB/m and negligible effective material loss of the structure of 0.02 cm−1. After all, we can say that abuse of drugs produces not only short-term effects but also long-term, catastrophic consequences for human health, including the potential for death. Therefore, it is essential to identify illegal drugs with high efficiency and precision. So, this H-PCF structure that we have proposed will be ideal for illegal drug detection.