Analysis and performance of edge filtering interrogation scheme for FBG sensor using SMS fiber and OTDR

Abstract

An interrogation technique for fiber Bragg grating (FBG) sensor is devised with customized in-line edge filtering single-multi-single mode fiber (SMS) component and optical time-domain reflectometer (OTDR). The performance of the proposed SMS-OTDR interrogation is established by temperature and strain sensing analysis of a standard FBG. The temperature and strain sensitivity values which are verified by theoretical analysis are estimated as 1.01 × 10−2 dB/℃ and 3.9 × 10−4 dB/µɛ respectively. Furthermore, we have optimized and achieved controlled etching on FBG and tested it for hiking the sensitivity. Using the etched FBG, an enhanced temperature and strain sensitivity of 6.7 × 10−2 dB/℃ and 3.2 × 10−3 dB/µɛ covering the range of 20–200 °C and 100–2015 µɛ respectively are also recorded and analysed by this integration method. Eventually, the efficiency and cost-effectiveness of the proposed method are compared with various reported techniques and presented here.

Keywords

• Interrogation technique
• Edge filter
• Fiber Bragg gratings (FBGs)
• Single-multi-Singlemode (SMS) fiber
• Optical time domain reflectometry
• Strain measurement