Bi-modal fibre-optical sensor with spatial demultiplexation.

摘要

Optical waveguide sensor propagating a first mode and giving rise to a second mode coupled to the first in response to disturbances caused by a physical or chemical quantity, of which it is desired to determine the amplitude and the position. The spatial separation (demultiplexing) of the modes is followed by a measurement of the luminous intensities of each mode, permitting the deduction of the amplitude of the disturbance. The multiplication of the luminous intensity signals and the determination of the phase of the signal thus obtained permits the determination of the position of the disturbance.