Compensation of temperature and strain coefficients due to local birefringence using optical frequency domain reflectometry

We demonstrate a high precision simultaneous temperature and strain measurement by means of polarization sensitive optical frequency domain reflectometry (OFDR). In the measurement, a high birefringence polarization maintaining (PM) fiber was used as sensor. It was confirmed that the thermal and strain coefficients of birefringence in PM fiber were position-dependent parameters, which can be used to compensate the errors of temperature and strain measurement. High accuracy simultaneous measurement of temperature and strain within errors 0.8 °C and 7 με was achieved with spatial resolution of 6.5 mm over 170 m fiber in this report.