A device. At least some example embodiments are a device including a filter element configured to receive optical energy from a first optical fiber. The filter element is reflective in a preselected band of optical wavelengths. A first lens is configured to receive optical energy transmitted through the filter element. A shell is disposed about the optical filter and the first lens; surfaces of the first lens, the filter element and the shell form a first boundary portion of an internal volume of an interior of the shell. A fluid is sealably disposed within the internal volume.

A DAS VSP technique is used to determine the induced fracture height and fracture density of an induced fracture region. The DAS VSP technique obtains pre-hydraulic fracturing DAS VSP survey time-lapse data to establish a baseline reference for the direct acoustic wave travel time. The DAS VSP technique obtains one or more time-lapse data corresponding to the subsequent monitor surveys conducted after each hydraulic fracturing stage along the well. Forward modeling is used to determine a theoretical acoustic wave travel time difference. The forward modeling uses seismic anisotropy to describe the behavior of seismic waves traveling through the induced fracture regions. An inversion scheme is then used to invert for the induced fracture height and the fracture density using the forward modeling. The two extracted induced fracture characteristics may then be used to determine optimal hydraulic fracturing parameters.

Apparatus for monitoring a building having a plurality of rooms. A plurality of beacons is each arranged to transmit a light output signal. The apparatus also comprises a plurality of waveguides suitable for deployment in the building so that each of the plurality of rooms has at least one of the waveguides arranged to receive the light output signal from one or more of the beacons when said one or more of the beacons is active in that room. There is at least one signal capture unit arranged to receive, via the waveguides, the light output signals resulting from the beacons in the rooms. A signal processor is arranged to distinguish, in use, the light output signal from a first beacon in a first room from the light output signal from a second beacon in a second, different, room.

Apparatus for monitoring a building having a plurality of rooms. A plurality of beacons is each arranged to transmit a light output signal. The apparatus also comprises a plurality of waveguides suitable for deployment in the building so that each of the plurality of rooms has at least one of the waveguides arranged to receive the light output signal from one or more of the beacons when said one or more of the beacons is active in that room. There is at least one signal capture unit arranged to receive, via the waveguides, the light output signals resulting from the beacons in the rooms. A signal processor is arranged to distinguish, in use, the light output signal from a first beacon in a first room from the light output signal from a second beacon in a second, different, room.

A device. The device includes a substrate a substrate, a first optical waveguide disposed on the substrate and a second optical waveguide disposed on the substrate. The device further includes a coupling element disposed on the substrate, the coupling element configured to couple an optical signal in the first optical waveguide to the second optical waveguide, and couple an optical signal in the second optical waveguide to the first optical waveguide. A first reflective element is disposed at an end of the first optical waveguide configured to reflect optical signals in the first optical waveguide. A second reflective element disposed at an end of the second optical waveguide configured to reflect signals in the second optical waveguide.

Various embodiments include apparatus and methods structured to interrogate a plurality of sensor assemblies, where each sensor assembly may have one or more transmissive optical sensors. The plurality of sensor assemblies can be arranged to couple between two optical fibers. The interrogation can include generating optical signals to each sensor assembly such that each sensor assembly can be selectively and individually interrogated using semiconductor optical amplifiers. Additional apparatus, systems, and methods are disclosed.

Various embodiments include apparatus and methods structured to interrogate a plurality of sensor assemblies, where each sensor assembly may have one or more transmissive optical sensors. The plurality of sensor assemblies can be arranged to couple between two optical fibers. The interrogation can include generating optical signals to each sensor assembly such that each sensor assembly can be selectively and individually interrogated using semiconductor optical amplifiers. Additional apparatus, systems, and methods are disclosed.

The present invention provides a marine cable device configured for preventing or reducing biofouling along its exterior surface, which during use is at least temporarily exposed to water. The marine cable device according to the present invention comprises at least one light source configured to generate an anti-fouling light and at least one optical medium configured to receive at least part of the anti-fouling light. The optical medium comprises at least one emission surface configured to provide at least part of said anti-fouling light on at least part of said exterior surface.

A vibration measurement system and relative method to monitor multiphase flows in extraction wells or conduits, by analysis of backscattered multimode fiber light comprising: • a sensing multimode optical fiber; • an optical source, containing a high coherence laser that emits optical pulses to be sent in said sensing fiber; • a photonic lantern with 3 or more single-mode optical fiber ports and one multimode fiber port that is connected to the sensing multimode fiber; • an optical receiver, comprising a number of photodetectors equal to the number of the single-mode optical fiber ports of said photonic lantern minus 1, wherein each photodetector is connected to each of said single-mode ports; • a system for processing output signals from the optical receiver, the optical source being connected to one of the single-mode optical fiber ports and the other single-mode fibers being connected to the optical receiver. A process is also described for reconfiguring an optical reflectometry system already installed at a facility to be monitored.

A system includes a drillstring with an electromagnetic (EM) transmitter in a first borehole. The system also includes at least one fiber optic sensor deployed in a second borehole. The system also includes a processor configured to demodulate a data stream emitted by the EM transmitter based on EM field measurements collected by the at least one fiber optic sensor.