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In this paper we discuss two particular topologies of fiber-optic sensors developed recently at the Laboratory of Optoelectronics at UQAH, based on pressure induced birefringence effects occurring in HB fibers, and both in temperature-compensating configurations. We present a thorough analysis of the performance of our first industrial prototype of fiber-optic stress cell developed around the concept of polarimetric pressure sensor. This prototype is based on all- fiber configuration and uses a Corning highly birefringent fiber for sensing, for temperature compensation and for transmission of light signal; a 3M polarizing fiber is also employed as a distributed polarizer. The leading input and output HB fibers are connectorized to the semiconductor laser diode and to the portable electronic detection unit. Metrological data presented in this paper show an overall accuracy of the system better than 1% of full scale in the pressure range up to 21 MPa, including stability, repeatability and temperature drift in the range of about 35 degree(s)C. Both pressure hysteresis effects and sensitivity of the leading fibers to external perturbations are negligible, and the excellent power budget of the sensor allows for remote operation up to several kilometers. The paper presents also a novel configuration of the white-light interferometric pressure sensor based entirely on HB fibers and employing electronic scanning to improve mechanical stability of the receiving interferometer, where the white-light interference pattern registered by the CCD detector is transversally shifted with pressure. We present metrological evaluation of the laboratory prototype of this sensor for the pressures up to 40 MPa for the temperatures from 10 to 35 deg. C. We also evaluate the application of coherence multiplexing for networking this type of sensors.
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