Abstract: An interferometric system with multi-axis optical fiber and a method for processing an interferometric signal in such a system, the multi-axis interferometric system includes a light source (1); a plurality of N optical-fiber coils (11, 12), a first optical separation element (3) capable of splitting the source beam (100) into a first split beam (140) and a second split beam (240); shared phase-modulation element (4); a photodetector (2) and a signal-processing system (800). The N optical-fiber coils (11, 12) are connected in parallel, the coils having respective transit times T1, T2, . . . TN that all differ from one another, and the signal-processing system (800) is capable of processing the interferometric signal (720) detected by the shared photodetector (2) as a function of the respective transit times in the various coils.

Abstract: A fiber-optic measurement device (10) includes a SAGNAC ring interferometer (20) having a proper frequency fp, a detector (14) and a modulation chain (30) generating a phase-shift modulation ?m(t) between the two counter-propagating waves (24, 25) propagating in the ring interferometer. The device aims to reduce measurement faults due to the linearity defects in the modulation chain of such a measurement device with optical fiber. For this reason, the fiber-optic measurement device reduces the amplitude of the phase-shift modulation ?m(t) which is the sum of a first biasing phase-shift modulation component ?b1(t) and a first counter-reaction phase-shift modulation component ?cr1(t), the phase-shift modulation ?m(t) falling or rising by twice the amplitude of the first biasing phase-shift modulation component ?b1(t). A rate gyro including such a measurement device and an inertial stabilization or navigation unit including at least one such rate gyro are also described.

Abstract: An interferometric system with multi-axis optical fiber and a method for processing an interferometric signal in such a system, the multi-axis interferometric system includes a light source (1); a plurality of N optical-fiber coils (11, 12), a first optical separation element (3) capable of splitting the source beam (100) into a first split beam (140) and a second split beam (240); shared phase-modulation element (4); a photodetector (2) and a signal-processing system (800). The N optical-fiber coils (11, 12) are connected in parallel, the coils having respective transit times T1, T2, . . . TN that all differ from one another, and the signal-processing system (800) is capable of processing the interferometric signal (720) detected by the shared photodetector (2) as a function of the respective transit times in the various coils.

Abstract: A fibre-optic measurement device (10) includes a SAGNAC ring interferometer (20) having a proper frequency fp, a detector (14) and a modulation chain (30) generating a phase-shift modulation ?m(t) between the two counter-propagating waves (24, 25) propagating in the ring interferometer. The device aims to reduce measurement faults due to the linearity defects in the modulation chain of such a measurement device with optical fibre. For this reason, the fibre-optic measurement device reduces the amplitude of the phase-shift modulation ?m(t) which is the sum of a first biasing phase-shift modulation component ?b1(t) and a first counter-reaction phase-shift modulation component ?cr1(t), the phase-shift modulation ?m(t) falling or rising by twice the amplitude of the first biasing phase-shift modulation component ?b1(t). A rate gyro including such a measurement device and an inertial stabilization or navigation unit including at least one such rate gyro are also described.

Abstract: A magneto-optical read head for detecting magnetic transitions representing data stored in a magnetic recording medium as a sense layer having an optical property that is magnetic field-dependent, two magnetic shield layers respectively disposed on opposite sides of the sense layer and allowing magnetic flux from substantially only one of the magnetic transitions to interact with the sense layer at a time, with one of the magnetic shield layers being transparent at a wavelength allowing light at that wavelength to enter into and exit from the sense layer.

Abstract: A magneto-optical read head for detecting magnetic transitions representing data stored in a magnetic recording medium as a sense layer having an optical property that is magnetic field-dependent, two magnetic shield layers respectively disposed on opposite sides of the sense layer and allowing magnetic flux from substantially only one of the magnetic transitions to interact with the sense layer at a time, with one of the magnetic shield layers being transparent at a wavelength allowing light at that wavelength to enter into and exit from the sense layer.