EFPI-RFBG based wide-range strain measurement of SiC structures in high temperature

To accurately obtain structural strength data for silicon carbide (SiC) components in high-temperature environments, this article develops a composite fiber optic sensor suitable for high-temperature large strain measurements on SiC structures. This EFPI-RFBG sensor is compact, low-cost, and easy to prepare, combining Extrinsic Farby-Perot Interferometric (EFPI) and Regenerated Fiber Brags Grating (RFBG) technologies to achieve dual-parameter measurement of temperature and strain for SiC structures. Experimental results show that the sensor has good measurement capabilities for both temperature and strain in the range of 100°C to 850°C, with strain sensitivity of 6.63 nm/μɛ and temperature sensitivity of 15.3 pm/°C. The temperature and strain measurement accuracy are 0.13°C and 0.15 μɛ respectively.