S-shaped tellurite optical fiber surface plasmon resonance sensor for temperature and refractive index measurement

Abstract

In this paper, an all-fiber S-shaped structure optical fiber surface plasmon resonance (SPR) sensor is proposed for temperature and refractive index measurement. The sensor is made of a single-mode tellurite optical fiber (TOF), and the middle part of the single-mode TOF is heated by a ceramic heating rod to form an S-shaped sensing region, and a 50 nm gold film is deposited in the S-shape sensing area to excite SPR. Based on the excellent properties of tellurite optical fiber, the prepared optical fiber sensor can be used for high sensitivity temperature and refractive index detection. The highest refractive index sensitivity is up to 1068.59 nm/RIU in the range of 1.333–1.380, and the temperature sensitivity is up to −0.713 nm/°C in the range of 30–150 °C. The proposed sensor is simple to fabricate, low-cost, and compact, and can be widely used in biochemical analysis, complex environmental temperature monitoring and other fields.