Electronically scanned white-light interferometric strain sensor employing highly birefringent fibers

Abstract An electronically scanned strain sensor employing highly birefringent fiber as a sensing element and using a low-coherent light source is described. The sensor is composed of two sections of exactly equal length of HB fiber spliced at 90°. This structure compensates the spatial coherence mismatch which enables application of a Wollaston prism alone without expensive bulk delay line as a receiving interferometer, and assures good temperature stability of the sensor. Absolute measurements of strain within the range up to 4000 μstrain with apparent temperature cross-sensitivity less than 1.3 μstrain/°C are possible with this sensor.