A sensing apparatus includes a sheath, a central member disposed in the sheath, at least one optical fiber disposed with the central member, and a film adhesive disposed between the central member and the sheath, the film adhesive provided in one or more sheets or strips and disposed in one or more layers between the central member and the sheath, and the film adhesive attached to the sheath.

An integrated seismic system and method for monitoring seismic parameters of a subsurface structure is provided. The integrated seismic system includes a base station; a plurality of mobile satellite nodes, each of the plurality of mobile satellite nodes having sensor stations for collecting seismic data from the subsurface structure; and a fiber optic cable extending from the base station to the plurality of mobile satellite nodes and operatively linking the plurality of mobile satellite nodes and the sensor stations; the base station comprising: a light source for sending a light through the fiber optic cable, the light being distributed to the sensor stations and, in the sensor stations, experiencing a change or phase shift related to a physical property being measured; and a seismic acquisition unit for receiving seismic signals from the plurality of mobile satellite nodes via the fiber optic cable and generating seismic parameters therefrom.

An optical fiber structure according to the present application includes a cylindrical resin body, and a plurality of circumferential arrays of optical fiber bare wires disposed within the resin body and extending along a longitudinal direction of the resin body. The resin body includes a linear slit provided at a location intermediate the length of the resin body. The linear slit extends from an outer surface to an inner bore of the resin body and extending substantially parallel to the bare wires.

A feeding tube position confirmation device 102, operable to confirm the position of a predetermined portion of a medical feeding tube in a predetermined portion of a human or animal body, the position confirmation device comprising an optical waveguide 106 dimensioned to be insertable into the lumen of the feeding tube, the optical waveguide having a sensing distal end 108 comprising a distal end material and a sensing material mixed with the distal end material, the sensing material operable to provide a change in optical properties at the distal end 110 of the optical waveguide dependent on the environment to which the sensing distal end 108 of the waveguide is exposed. The sensing material may comprise a reflective material. Methods of manufacture and use of such devices are also described.

Double-clad optical fibers with polymer outer coatings are used in fiber amplifiers and fiber lasers to guide and amplify light. As the optical power increases, the optical fibers must dissipate more heat. Unfortunately, it is difficult to dissipate heat through a polymer cladding, especially at high altitude, without introducing phase noise in the optical signal. To overcome this problem, the inventors have realized metallized polymer-clad optical fibers with superior heat dissipation characteristics than conventional polymer-clad optical fibers. An example metallized polymer-clad optical fiber includes a thin chrome layer that is vacuum-deposited onto the polymer cladding at low temperature, then electroplated with a thicker copper layer. In operation, the copper layer dissipates heat from within the fiber's core and claddings via a heatsink, enabling the fiber to guide and amplify high-power optical signals at high altitude.

There is described a method of fabricating an optical fiber device, the method comprising: positioning longitudinal portions of a plurality of optical fibers alongside each other in a given geometrical relationship, depositing liquid coating material around the longitudinal portions of the plurality of optical fibers; and the liquid coating material setting up around the longitudinal portions of the plurality of optical fibers thereby maintaining said given geometrical relationship along the longitudinal portions.

Embodiments include an optical fiber cable comprising a length extending between a first end and a second end, a central cooling tube, a plurality of optical fibers disposed radially around the cooling tube, each optical fiber comprising a fiber core and a cladding disposed around the fiber core, an outer protective cover, and an inner thermal filler disposed between the outer protective cover and the central cooling tube and surrounding each of the optical fibers, wherein each of the central cooling tube, the outer protective cover, the inner thermal filler, and the plurality of optical fibers extend the length of the cable. Various systems and methods for removing imperfections from individual optical fibers and for distributing power across long distances using the optical fiber cable are also provided.

An optical fibre assembly comprises a hollow core optical waveguide comprising a hollow core surrounded by a structured arrangement of longitudinally extending capillaries providing an inner cladding surrounded by an outer cladding; a diagnostic solid core optical waveguide comprising a solid core surrounded by a cladding, and extending substantially parallel to the hollow core optical waveguide; and a jacket surrounding both the hollow core optical waveguide and the solid core optical waveguide and forming a common mechanical environment for the hollow core optical waveguide and the solid core optical waveguide. The optical fibre assembly may be or may comprise or be included in an optical fibre cable, and may be used in a method for testing hollow core optical waveguides.

Disclosed is an optical cable for distributed sensing. The optical cable comprises a first metal tube with at least two optical fibers loosely arranged therein and a second metal tube with at least two tight buffered optical fibers tightly arranged within an inner surface of the second metal tube. A third metal tube having an inner surface collectively surrounds and operatively contacts the first metal tube and said second metal tube. At least one of the first metal tube and the second metal tube is fixed by means of an adhesive compound to the inner surface of the third metal tube.

An optical fiber cable for sound wave sensing that uses a straight optical fiber and is capable of suppressing directivity is provided. The optical fiber cable for sound wave sensing includes a cover part (10) that is capable of covering a straight cable core (11) and is provided with a sound wave refraction part (12) which refracts sound waves made incident roughly perpendicularly to a longitudinal direction of the cable core (11) and makes the sound waves be incident diagonally to the longitudinal direction of the cable core (11). The cover part (10) includes a gap filling part (23) which covers the sound wave refraction part (12).