Simultaneous measurement of temperature and refractive index based on an SPR Silicon core fiber sensor with a fused silica grating design

Abstract

This paper proposed a fiber sensor based on a Silicon core fiber incorporated with a fused silica grating design. The proposed structure is a nice sensitive in refractive index and temperature variation through theoretical calculation and finite element method simulation. The sensitivities of the refractive index in different polarization directions are 1838.7 and 1949.8 nm/RIU, respectively, within the index range from 1.28 to 1.38 RIU. The temperature range within 15 to 40 o C has the sensitivity up to 1.6 nm/ o C by using ethanol analyte. The proposed fiber sensor can provide a method or a solution for intelligent sensing systems.

Research Advances on Fiber-Optic SPR Sensors with Temperature Self-Compensation

“…Figure 6 c shows the temperature self-compensation composite refractive index sensor based on tilted fiber grating and SPR technology proposed by Shao et al [ 63 ]. In addition, Yu et al [ 64 ] designed a temperature self-compensated refractive index sensor with a silicon core surface grating structure, as shown in Figure 6 d. The surface grating is obtained by photolithography of silicon core fibers after side polishing, and the SPR resonance absorption peak is excited by plating a 2 nm gold film on the surface of the grating. Then, a double peak is generated based on the coupling between the core and SPR modes with different refractive indices in the X and Y polarization directions.…”

“… The structure of fiber grating sensing head ( a ) Bragg grating structure [ 61 ]; ( b ) long-period fiber grating structure [ 62 ]; ( c ) tilted fiber grating structure [ 63 ]; ( d ) surface grating structure [ 64 ]. …”