Highly sensitive fiber-optic sensor for dynamic pressure measurements

A new type of fiber-optic pressure sensor based on highly birefringent fibers is presented. To assure temperature desensitization, the sensing part of the device is composed of specially developed side-hole fiber and elliptical core fiber, which are spliced to each other with polarization axes rotated by 90 degrees. Such sensor construction assures high sensitivity to pressure and compensation of temperature effects associated with rapid pressure changes. The sensor allows for unambiguous and fast phase-shift measurements in the range from -pi/2 to +pi/2 with a sampling rate of 5 kHz and resolution of about 0.5% of full scale (2.10(-3) atm). The sensor calibration procedure, responses to fast pressure change, and preliminary applications are demonstrated.