No-core optical fiber sensor based on surface plasmon resonance for temperature measurement

A simple single-mode fiber/no-core fiber/single-mode fiber (SMF-TNCF-SMF) based on multimode interference (MMI) and surface plasmon resonance (SPR) sensing configuration has been design and demonstrated. The sensor has been constructed by fusing a spliced section of etched no-core fibre (NCF) fused between two pieces of single-mode fiber and an etched region coated with a layer of gold-film. The experimental results showed that the sensor has a temperature sensitivity of -0.48565 dB$/ ^{\circ}\mathrm{C}$, with a good correlation coefficient $( \mathrm{R}^{2})$ of about 97.25% in the temperature range $22-55 ^{\circ}\mathrm{C}$. The experimental results are useful in terms of indicating the possibility of being able to fabricate an SPR sensor configuration with superior sensing performance. The indicated sensor configuration has the benefits of ease of use, simple assembly, cost-effectiveness, excellent durability, which means there is a wide range of performance for different applications, including various chemical and biological analyzes as well as in the medical device industry.