Abstract: The present invention provides novel apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fibre. The present invention can be used for point sensors as well as distributed sensors or the combination of both. In particular this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fibre while achieving fine spatial resolution. The present invention offers unique advantages in a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.

Abstract: Exemplary embodiments include an apparatus for imaging a volume of material contained inside a vessel. The apparatus includes a plurality of synchronized acoustic sensors positioned at a periphery of an inner volume of the vessel. A processor combines the outputs of the acoustic sensors to identify at least one ambient noise source of the industrial process generating a noise field that illuminates an internal volume of the vessel and to provide an image of the material by temporal and spatial coherent processing of the transmission and reflection of the noise field generated by the noise source.

Abstract: Apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fibre can be used for point sensors as well as distributed sensors or the combination of both. In particular, this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fibre while achieving fine spatial resolution. Advantages of this technique include a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.

Abstract: The present invention provides novel apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fiber. The present invention can be used for point sensors as well as distributed sensors or the combination of both. In particular this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fiber while achieving fine spatial resolution. The present invention offers unique advantages in a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.

Abstract: An interferometer apparatus for an optical fiber system and method of use is described. The interferometer comprises an optical coupler and optical fibers which define first and second optical paths. Light propagating in the first and second optical paths is reflected back to the optical coupler to generate an interference signal. First, second and third interference signal components are directed towards respective first, second and third photodetectors. The third photodetector is connected to the coupler via a non-reciprocal optical device and is configured to measure the intensity of the third interference signal component directed back towards the input fiber. Methods of use in applications to monitoring acoustic perturbations and a calibration method are described.

Abstract: Exemplary embodiments include an apparatus for imaging a volume of material contained inside a vessel. The apparatus includes a plurality of synchronized acoustic sensors positioned at a periphery of an inner volume of the vessel. A processor combines the outputs of the acoustic sensors to identify at least one ambient noise source of the industrial process generating a noise field that illuminates an internal volume of the vessel and to provide an image of the material by temporal and spatial coherent processing of the transmission and reflection of the noise field generated by the noise source.

Abstract: Exemplary embodiments include an apparatus for imaging a volume of material contained inside a vessel. The apparatus includes a plurality of synchronized acoustic sensors positioned at a periphery of an inner volume of the vessel. A processor combines the outputs of the acoustic sensors to identify at least one ambient noise source of the industrial process generating a noise field that illuminates an internal volume of the vessel and to provide an image of the material by temporal and spatial coherent processing of the transmission and reflection of the noise field generated by the noise source.