High-sensitive fiber taper-sphere probe based on polydimethylsiloxane-packaged for measurement of transverse load and temperature

Abstract

A high sensitive reflective fiber taper-sphere sensing probe wrapped by a polydimethylsiloxane (PDMS) sphere is proposed for measurement of transverse load and temperature simultaneously. First, a fiber taper probe is prepared, and its end is melted into a microsphere to improve the quality of the spectrum. Then, the fiber taper-sphere is wrapped by a PDMS sphere, and the proposed fiber sensing probe is obtained. The diameter of PDMS sphere is 950 μm. In the whole process of preparation, only a fusion splicer and a temperature box are used. Because the PDMS surrounds the fiber taper-sphere firmly, the mechanical strength of the proposed fiber sensing probe is good. With the transverse load and the temperature varying, the shifts of two interference peaks in spectrum are monitored. The transverse load sensitivities can reach 1756.7 nm/N and 1780.1 nm/N, and the temperature sensitivities are 789.1 pm/℃ and 644.7 pm/℃, respectively. Both the transverse load and the temperature can be measured simultaneously by using the method of sensing matrix. The transverse load sensitivity of our fiber sensing probe is significantly improved. It will has important application prospects in the fields of safety monitoring, aerospace and automotive industry due to high sensitivities, good mechanical strength, ease fabrication and low cost.