Abstract: A system and method for determining a partial pressure of hydrogen in a volume. A response is measured of a section of an optical fiber disposed in the volume to a parameter of the volume. A partial pressure of hydrogen in the volume is determined from the response of the optical fiber to the parameter. The presence of hydrogen in the volume is determined from the partial pressure of hydrogen.

Abstract: An apparatus and method of embedding an optical fiber within a substrate. The apparatus includes a bonding device and a conveyance device. The bonding device bonds a foil layer to the substrate to seal the optical fiber within a groove of the substrate. The conveyance device moves the substrate and the bonding device relative to each other. Relative motion between the substrate and the bonding device draws the optical fiber into the groove and the foil layer over the optical fiber at a collection point.

Abstract: An optical system employs a method for measuring an acoustic signal in a wellbore. The optical system includes an optical interrogator and an optical fiber. The optical fiber has a plurality of nominal sites uniformly spaced apart along a longitudinal axis of the optical fiber. A plurality of gratings are formed in the optical fiber. Each of the plurality of gratings is associated with a nominal site and is separated from its associated nominal site by an offset distance. The offset distance is selected to reduce a destructive interference between reflections from the plurality of gratings. The optical interrogator transmits a light pulse into the optical fiber to measure the acoustic signal via a reflection of the light pulse from at least one of the plurality of gratings.

Abstract: An optical system performs a method for measuring an acoustic signal in a wellbore. The optical system includes a light source, an optical fiber and a detector. The light source generates a light pulse. The optical fiber has a first end for receiving the light pulse from the light source and a plurality of enhancement scatterers spaced along a length of the optical fiber for reflecting the light pulse. A longitudinal density of the enhancement scatterers increases with a distance from the first end to increase a signal enhancement generated by the enhancement scatterers distal from the first end. The detector is at the first end of the optical fiber and measures a reflection of the light pulse at the enhancement scatterers to determine the acoustic signal.

Abstract: An apparatus and method of embedding an optical fiber within a substrate. The apparatus includes a bonding device and a conveyance device. The bonding device bonds a foil layer to the substrate to seal the optical fiber within a groove of the substrate. The conveyance device moves the substrate and the bonding device relative to each other. Relative motion between the substrate and the bonding device draws the optical fiber into the groove and the foil layer over the optical fiber at a collection point.

Abstract: A sensor and a method of manufacture of a sensor. The sensor includes a body having a groove therein, a first optical fiber and second optical fiber disposed in the groove, and a first layer and second layer bonded in the groove. The groove is formed in the body of the sensor. The first optical fiber is deposited in the groove. The first layer is bonded in the groove to form a first chamber in which the first optical fiber is disposed. The second optical fiber is disposed in the groove. The second layer is bonded in the groove to form a second chamber in which the second optical fiber is disposed.

Abstract: A system and a method of carbon capture. The system includes a volume having a gas mixture therein, an optical fiber and a processor. The gas mixture includes carbon dioxide as a component. The optical fiber has a coating sensitive to carbon dioxide to generate a strain on the optical fiber. The processor is configured to adjust an operating parameter of the system based on a presence of the carbon dioxide determined using the optical fiber.

Abstract: An optical system employs a method for measuring an acoustic signal in a wellbore. The optical system includes an optical interrogator and an optical fiber. The optical fiber has a plurality of nominal sites uniformly spaced apart along a longitudinal axis of the optical fiber. A plurality of gratings are formed in the optical fiber. Each of the plurality of gratings is associated with a nominal site and is separated from its associated nominal site by an offset distance. The offset distance is selected to reduce a destructive interference between reflections from the plurality of gratings. The optical interrogator transmits a light pulse into the optical fiber to measure the acoustic signal via a reflection of the light pulse from at least one of the plurality of gratings.

Abstract: An optical system performs a method for measuring an acoustic signal in a wellbore. The optical system includes a light source, an optical fiber and a detector. The light source generates a light pulse. The optical fiber has a first end for receiving the light pulse from the light source and a plurality of enhancement scatterers spaced along a length of the optical fiber for reflecting the light pulse. A longitudinal density of the enhancement scatterers increases with a distance from the first end to increase a signal enhancement generated by the enhancement scatterers distal from the first end. The detector is at the first end of the optical fiber and measures a reflection of the light pulse at the enhancement scatterers to determine the acoustic signal.

Abstract: An optical amplifier comprises at least two gain regions, an intermediate region situated between the gain regions, and a transition region situated between the intermediate region and each gain region. The aforesaid regions have claddings that collectively form a path for pump radiation propagating from at least one of the gain regions to the other gain region, and cores that collectively form a path for signal radiation propagating from at least one of the gain regions to the other gain region. The cores in the gain regions support multiple propagating optical modes, including at least one signal mode and at least one non-signal mode. The intermediate region, however, supports fewer propagating core modes than are supported by the gain regions. The transition regions are conformed such that when radiation in propagating non-signal core modes passes from the gain regions into the intermediate region, it is at least partly coupled into cladding modes of the intermediate region.

Abstract: An optical amplifier comprises at least two gain regions, an intermediate region situated between the gain regions, and a transition region situated between the intermediate region and each gain region. The aforesaid regions have claddings that collectively form a path for pump radiation propagating from at least one of the gain regions to the other gain region, and cores that collectively form a path for signal radiation propagating from at least one of the gain regions to the other gain region. The cores in the gain regions support multiple propagating optical modes, including at least one signal mode and at least one non-signal mode. The intermediate region, however, supports fewer propagating core modes than are supported by the gain regions. The transition regions are conformed such that when radiation in propagating non-signal core modes passes from the gain regions into the intermediate region, it is at least partly coupled into cladding modes of the intermediate region.

Abstract: A universal inline functional module for operation with nonzero average gain G?0 dB over a bandwith is provided. The module includes at least one optical functional element producing loss over the bandwidth and at least one rare-earth doped fiber segment. The module produces a flat gain spectrum to within a specified tolerance when made to operate at an average gain of 0 dB over the bandwidth.

Abstract: There is provided a method and apparatus for improved efficiency in optical fiber lasers. Specifically, there is provided a system that increases the efficiency of cladding pumped optical fiber amplifiers through a seeding technique.

Abstract: Systems and methods for monitoring signals in an optical fiber amplifier system are provided. The optical amplifier system includes a tapered fiber bundle which couples optical energy into the cladding of an optical amplifier. A signal passing through the optical amplifier is amplified. To monitor the amplified signal, a single fiber of a tapered fiber bundle may be used as a monitor fiber. Alternatively, a monitor or coupler may be integrated into the tapered fiber bundle during manufacturing. The systems and methods disclosed allow for monitoring the amplified signal without increasing the length of the amplified signal's path, thus minimizing the introduction of additional non-linearities.

Abstract: An improved tapered fiber bundle (TFB), or assembly including a TFB, mitigates undesirable reflections from optical discontinuities at the input ends of the multimode fibers of the TFB by suppressing the coupling of signal light into modes that can produce undesired reflections. Means are provided for managing the mode field of injected signal light so that it remains substantially confined to the core of the central TFB fiber until it is past the region where it can interact with the multimode fibers of the TFB.

Abstract: The present invention provides an apparatus comprising a passive optical transmission fiber. The passive optical transmission fiber comprises a passive glass fiber core, a glass optical inner cladding surrounding the core and a glass optical outer cladding surrounding the inner cladding. The inner cladding has a lower index of refraction than the passive glass fiber core and the outer cladding has a lower index of refraction than the inner cladding. The passive optical transmission fiber also comprises a second optical segment coupled to the optical fiber. The second optical segment is configured to dissipate light in the inner cladding.

Abstract: A multi-channel optical amplifier arrangement operating over a particular bandwidth is provided. The amplifier arrangement includes at least one optical amplifier stage that includes a rare-earth doped optical waveguide, at least one pump source for supplying optical pump energy to the doped optical waveguide, and at least one coupler for coupling the optical pump energy to the doped optical waveguide. The amplifier arrangement also includes a dynamic range enhancer (DRE) having an input and an output and a plurality of distinct optical paths each selectively coupling the input to the output. At least two of the optical paths produce different gain spectra across the particular operating bandwidth. The DRE further includes an optical path selector for selecting any optical path from among the plurality of optical paths such that for all channels in the particular bandwidth the selected path optically couples the input to the output of the DRE.