Analysis of filtering and refractive index sensing characteristics based on gold-coated photonic crystal fiber

A gold-coated photonic crystal fiber (PCF) with dual functions of filtering and refractive index sensing is proposed. The gold layer is deposited in two open grooves, which make it easy to manufacture. For the filtering characteristics, it can achieve high loss at the wavelength of 1550 nm. The results show that the confinement losses of the x- and y-polarized modes are 0.012 dB/cm and 445.10 dB/cm, respectively. When the crosstalk is greater than 20 dB, it shows high bandwidth of 910 nm for the PCF length of 3 mm. For the sensing characteristics, it shows a maximum sensitivity of 4000 nm/RIU for an analyte range of 1.39-1.40. It also has a high figure of merit with a maximum value of 45.45 RIU-1 and a low detection limit (56.13 nm). Owing to the excellent performance of the gold-coated PCF in filtering and sensing, it will become a suitable candidate for optical communication and sensing systems. (C) 2022 Optica Publishing Group