Independent measurement of refractive index and temperature using D-gapped dual-channel structure in a photonic crystal fiber

A dual-channel sensor was proposed by further processing a gap on the D-shaped surface of a photonic crystal fiber (PCF). The simultaneous and independent measurement for refractive index (RI) and temperature was theoretically demonstrated. On the dual-channel surfaces, the Ag films were elaborated to improve the sensing performance for RI based on surface plasmon resonance (SPR) effect. The sensing performance of the temperature channel was improved by further-overlaying the polydimethylsiloxane (PDMS) film. Furthermore, the TiO2 film was introduced to protect the silver away from oxidation and optimized the sensing performance. When the thickness of Ag film is 45 nm and the thickness of TiO2 film is 13 nm, the highest sensitivities of RI and temperature were respectively obtained as 6700 nm/RIU and - 21 nm/degrees C.

Automated summary

A dual-channel sensor for refractive index (RI) and temperature measurement was proposed by modifying the gap on the D-shaped surface of a photonic crystal fiber. The sensing performance for RI was improved by applying Ag films based on surface plasmon resonance (SPR) effect, while the temperature channel was enhanced by overlaying a PDMS film. Additionally, a TiO2 film was introduced to protect the Ag film from oxidation and optimize the sensing performance. The highest sensitivities of RI and temperature, achieved with an Ag film thickness of 45 nm and a TiO2 film thickness of 13 nm, were 6700 nm/RIU and -21 nm/degrees C respectively.