Infrared D-type photonic crystal fiber sensor for special drug detection and wide-range refractive index detection

Abstract

In the field of drug inspection, the refractive indices (RIs) of many halogenated ethers and drugs are in the lower range; for example, the RI of anesthetic sevoflurane is approximately 1.27. Infrared spectral detection technology has significant advantages in the field of drug detection; to realize the RI sensing of such drugs in the infrared region, a D-shaped photonic crystal fiber sensor based surface plasmon resonance was investigated in this study. The side polishing adopted here can significantly shorten the distance between the core and metal layer, making the energy of the core easier to detect, reducing the difficulty of coating the metal layer, and improving the performance of the sensor. The structure is provided with two large-sized air holes on both sides of the fiber core, so that the sensor is suitable for sensing in the low RI range and has high wavelength sensitivity in the low RI range. The sensor works mainly in the infrared band, with a detection range of 1.20–1.34, maximum wavelength sensitivity of 24,000 nm/RIU, and resolution of 4.1667 × 10 − 6 R I U . The sensor has excellent performance and is easy to manufacture due to the simple structure; it has broad application prospects in low RI range detection fields such as biomedicine, drug detection, environmental monitoring, and water quality monitoring.