Design of high-sensitivity photoelastic optical fiber pressure sensor: a differential approach

A differential method is described for an optical fiber photoelastic pressure sensor to implement high sensitivity and low drift optically. The method relies on importing two orthogonal polarization light beams into the system alternately in time to produce two differential output signals that are derived from conventional compensation methods. The difference of the two output signals can reduce the long-term drift significantly. The measurement range of 0/spl sim/0.15 MPa has been demonstrated with an accuracy of 0.1% within the temperature range of -20/spl deg/C/spl sim/50/spl deg/C. The practical application proves its efficiency.