Distributed feedback fiber laser sensor for hydrostatic pressure

A polarimetric distributed feedback fiber laser sensor for the measurement of fluid pressure up to 50 MPa is investigated between room temperature and 250/spl deg/C. The isotropic pressure acts directly on the fiber, which eliminates the need of a mechanical transducer. A pressure resolution of about 20 kPa (0.2 bar) is demonstrated. Furthermore, the protection of the silica fiber against deterioration by the fluid and the thermomechanical effects of various fiber coatings on the sensor response are studied.