DISTRIBUTED SENSOR OF ACOUSTIC AND VIBRATION ACTION Russian patent published in 2015 - IPC G01D5/353 G01H9/00 

FIELD: physics.

SUBSTANCE: distributed sensor of acoustic and vibration action comprises a sensitive element in the form of an optical fibre placed in a fibre-optic cable, and a coherent phase-sensitive optical reflectometer optically connected to the fibre through an interface. The sensor also includes a source of a periodic sequence of optical test signals connected to the interface, said source being in the form of a series of optically connected continuous laser, an acoustic travelling wave acoustooptical modulator and a scattered radiation receiver. Said source is configured to generate test signals in the form of a pair of equal-duration pulses with delay of the second pulse relative to the first pulse and periodically variable phase delay of the optical carrier wave of the second pulse relative to the phase of the optical carrier wave of the first pulse.

EFFECT: achieving linear response of the device to external action, providing uniform distribution of sensitivity along the length of the fibre and low probability of occurrence of dead space.

7 cl, 1 tbl, 4 dwg