Optical fiber pressure sensor based on photoelasticity and its application

An optical fiber pressure sensor based on the photoelastic effect using a novel compensation technique is described. Two optical sources and a polarization-splitting prism are incorporated into a sensor system to minimize output drifts. The four major factors-the optical source power, the fiber loss, the optical coupling loss, and the modal power distribution in fibers-are well compensated. The measurement range of 0-147 kPa has been obtained with accuracies of 0.2% within the temperature range of -10 degrees C to 42 degrees C and a resolution of 10 Pa has been achieved. Compensation for fiber loss has been observed up to -30 dB. This sensor system has been successfully put into practical operation for oil storage measurement in a tank.>