High-precision temperature-compensated fiber Bragg grating axial strain sensing system based on a dual-loop optoelectronic oscillator with the enhanced Vernier effect

, and the maximum temperature compensation error is as low as 0.024°C in the dual-loop OEO, which is far less than that in the single-loop OEO. The enhanced Vernier effect not only improves the sensitivity, but also reduces the temperature compensation error.