FIBRE OPTIC MEASURING DEVICE, RATE GYRO, STABILISATION SYSTEM AND MAGNETIC FIELD OR CURRENT SENSOR

摘要

FIBRE OPTIC MEASURING DEVICE, RATE GYRO, STABILISATION SYSTEM AND MAGNETIC FIELD OR CURRENT SENSOR. The invention relates to a fibre optic measuring device in which the variation in a measured parameter engenders a phase difference between two waves. It comprises a SAGNAC ring interferometer (2) in which two counter-propagating waves propagate; a polarisation splitter (6) spatially splits the two polarisations which will propagate in the interferometer (2), the interferometer (2) comprises a polarisation conserving birefringent fibre (7) having two ends having neutral birefringence axes, each of the ends of the polarisation conserving fibre (7) being connected to one of the gates (6b) and (6c) of the polarisation splitter (6). It comprises a birefringent component, placed ahead of the polarisation splitter (6) and introducing a path difference greater than the coherence length of the source (1) between the two polarised waves. FIGURE 1.