Abstract: A fiber-optic sensor array (100) comprises a line array of fiber-optic sensor packages (AX, BX, CX, DX, AY, BY, CY, DY, AZ, BZ, CZ, DZ) each having a package input/output (i/o) fiber and each being arranged to output a finite output pulse series of optical output pulses via the package i/o fiber in response to input thereto of one or more interrogating optical pulses. The array further comprises a fiber-optic bus (104,106, 108, 110) extending along the length of the line array, each package i/o fiber being optically coupled to the fiber-optic bus at a respective positions along the line array. The array allows interrogation at a higher frequency than is the case for a serial array of the same number of fiber-optic sensing packages.

Abstract: A fibre-optic sensor array (100) comprises a line array of fibre-optic sensor packages (AX, BX, CX, DX, AY, BY, CY, DY, AZ, BZ, CZ, DZ) each having a package input/output (i/o) fibre and each being arranged to output a finite output pulse series of optical output pulses via the package i/o fibre in response to input thereto of one or more interrogating optical pulses. The array further comprises a fibre-optic bus (104,106, 108, 110) extending along the length of the line array, each package i/o fibre being optically coupled to the fibre-optic bus at a respective positions along the line array. The array allows interrogation at a higher frequency than is the case for a serial array of the same number of fibre-optic sensing packages.

Abstract: An optical sensor assembly comprising a plurality of optical fibre sensor coils optically coupled by optical fibre; and an elongate support element, on which said plurality of optical fibre sensor coils and optically coupling optical fibre are mounted is disclosed. The support element has an elastic limit such that when said support element is bent from the elongate axis, the optical fibre fracture limit is reached before the elastic limit is reached. An array of these optical sensor assemblies, the mandrel on which the sensing coils are mounted and their method of manufacture are also disclosed.

Abstract: Attached to a cable having a central strength member is an optical sensor assembly. The sensor assembly comprises a coupler and an optical fibre coil. The coupler is attached to the central member of the cable at a position where outer layers of the cable been removed. A first terminal of the coupler is connected to an optical fibre traveling along the cable in a fibre conduit external to the central strength member. A second terminal of the coupler is connected to a first end of the coil and a third terminal of the coupler is connected to an optical fibre a mirrored end. The coil is supported about a tubular mandrel, which mandrel fits over the cable. The other end of the coil is attached to the fibre in the cable. The mandrel is located about the cable at a position covering the coupler and the part of the cable where the outer layers are removed. The whole assembly is covered with a waterproof layer sealing it to the cable.