Measurement of Strain Sensitivity of OFDR Fiber Based on Moving Microscope Stretching Method

Strain sensitivity is an important index of OFDR fiber performance indicators, because it is related to aerospace, civil construction and many other fields of accurate strain monitoring and structural safety assessment, so it is imperative to carry out precision measurement to ensure data accuracy, structural reliability, material research and development optimization and high-precision engineering applications. Therefore, the Measurement of strain sensitivity of OFDR fiber based on moving microscope stretching method is proposed. First, the marker measuring section of the specific position of the optical fiber is used as the marker distance, and the double microscope system is used to accurately locate the marker before and after the stretching by using its high resolution imaging capability. Then the frequency shift of Rayleigh scattering is measured by OFDR equipment, and the strain sensitivity is determined by correlation analysis with the measured strain value. Finally, the uncertainty evaluation is carried out. The results show that the strain sensitivity of the fiber is 0.1567 MHz/me, and the uncertainty is 0.0004 MHz/me. The innovative breakthrough of OFDR fiber strain sensitivity measurement is realized, which also has certain reference value for other types of distributed fiber in related measurement, and helps to promote the further development and improvement of distrib-uted fiber measurement technology.