A guidewire having a fiber optic force sensor with a mirror having encoded reflectance is described. The guidewire has a distal housing supported by a core wire. A distal hypotube connected to the distal housing supports a spring intermediate hypotube proximal and distal portions. An atraumatic head is connected to the distal hypotube portion. An optical fiber having at least one fiber core extends through lumens in the core wire and housing to a distal end of the housing. A mirror supported by the atraumatic head faces proximally but is spaced distally from the fiber core at a distal face of the optical fiber. The mirror is provided with a pattern of reflectance that varies along a radius from a central area of reflectance. Light of a defined power shines from the fiber core to the mirror with a reflected percentage of the defined light power being reflected back to the fiber core. A percentage of the reflected percentage of the defined light power is captured by and travels along the fiber core to a light wave detector connected to a controller. From the percentage of the reflected percentage of the light of the defined power received by the detector, the controller is programmed to calculate whether an axial or lateral force is imparted to the atraumatic head and, if so, the magnitude and vector of those forces.

Aspects of the subject technology relate to systems and methods for determining positions of fluids during a cementing process in real-time. Systems and methods are provided for receiving one or more sensing parameters from a distributed acoustic sensing fiber optic line positioned in a wellbore during a cementing process, determining types of fluid proximate to the wellbore based on the one or more sensing parameters received from the distributed acoustic sensing fiber optic line, determining pressure gradients of the types of fluid based on the one or more sensing parameters received from the distributed acoustic sensing fiber optic line, and compiling flow profiles for the types of fluid proximate to the wellbore based on at least one of the determining of the types of fluid and the determining of the pressure gradients of the types of fluid.

An opto-mechanical resonator including a waveguide formed by a plurality of first strips spaced apart from one another; and two mirrors disposed facing one another, which mirrors are optically reflective over at least part of a guide wavelength range of the waveguide. The waveguide extends between the two mirrors, and forms therewith an optically resonant cavity. At least part of the waveguide is held such that it is suspended over a substrate by at least one deformable mechanical element.

An apparatus is disclosed for capturing image information. The apparatus includes a waveguide having opposed planar input and output faces. A diffractive optical element (DOE) is formed across the waveguide. The DOE is configured to couple a portion of the light passing through the waveguide into the waveguide. The light coupled into the waveguide is directed via total internal reflection to an exit location on the waveguide. The apparatus further includes a light sensor having an input positioned adjacent the exit location of the waveguide to capture light exiting therefrom and generate output signals corresponding thereto. A processor determines the angle and position of the coupled light with respect to the input face of the waveguide based on the output signals.

A production monitoring system includes a distributed acoustic sensing subsystem that includes a first optical fiber for a distributed acoustic sensing signal and a distributed temperature sensing subsystem that includes a second optical fiber for a distributed temperature sensing signal. The production monitoring system, also includes a cable positioned in a wellbore penetrating through one or more subterranean formations. The distributed acoustic sensing subsystem is communicatively coupled to the cable through the distributed temperature sensing subsystem. The cable includes one or more optical fibers used to obtain optical fiber measurements pertaining to the distributed acoustic sensing signal and the distributed temperature sensing signal. The optical fibers include a sensing fiber that is common between the distributed acoustic sensing subsystem and the distributed temperature sensing subsystem. The distributed acoustic sensing subsystem, receives at least a portion of the optical fiber measurements from the sensing fiber through the distributed temperature sensing subsystem.

Technologies for propagating optical information through an optical waveguide in a downhole environment are provided. An example method can include generating a light signal via a light-emitting device at a first location on a wellbore environment; propagating the light signal through an optical waveguide on an inner surface of a wellbore tool, the optical waveguide including a first layer of low refractive-index material, a second layer of high refractive-index material applied to a first surface of the first layer, and a third layer of low refractive-index material applied to a second surface of the second layer; and receiving, by a detector at a second location on the wellbore environment, the light signal via the optical waveguide on the inner surface of the wellbore tool.

A method of detecting removal of a maintenance hatch includes transmitting an optical pulse along an optical fiber, wherein a first portion of the optical fiber is proximate to the maintenance hatch. The method further includes detecting backscatter light from the optical fiber using a sensor. The method further includes determining information related to the first portion of the optical fiber based on a comparison of the detected backscatter light and a trained model. The method further includes identifying whether the maintenance hatch has been removed based on the determined information.

There is provided a test method and system for characterizing an optical fiber link. At least one OTDR acquisition or at least one OLTS acquisition is performed on the optical fiber link. From the acquisition, a value of an excess insertion loss and/or an excess optical return loss associated with the optical fiber link under test is derived, i.e. in excess of a nominal value associated with a hypothetical optical fiber link having a length corresponding to the total length of the optical fiber link under test. A rating value (e.g., as a five-star rating) or a binary pass/fail value associated with the optical fiber link under test can then be derived and displayed.

A fiber-optic sensors for measuring deformation, intended to operate in a harsh environment is provided. The sensor comprises a Fabry-Perot-cavity-based optical measurement head, a linking optical fiber and an expansion reserve case, the case comprising a segment of the linking optical fiber. The inside thickness of the case is comprised between one and several millimeters, the case being flat and of shape referred to as bicorne shape, the shape comprising a convex central portion and two concave symmetric ends, the optical fiber forming, inside the bicorne, one and only one arch, the segment of the optical fiber being, in addition, tangent to the internal surfaces of the reserve case, whatever the temperature conditions.

Fiber-optic equipment is often deployed in various locations, and performance of fiber-optic transmissions may be monitored as a gauge of equipment status to prevent costly and inconvenient communication outages. Events that damage equipment that eventually result in outage and may be desirable to address proactively, but the occurrence of such events may be difficult to detect only through equipment performance. Presented herein are techniques for monitoring and maintaining fiber-optic equipment performance via enclosure sensors that measure physical properties within a fiber-optic equipment enclosure, such as temperature, pressure, light, motion, vibration, and moisture, which are often diagnostic and predictive of causes of eventual communication outages, such as temperature-induced cable loss (TICL), incomplete flash-testing during installation, exposure to hazardous environmental conditions, and tampering. An enclosure sensor package transmits the physical measurements to a monitoring station, and automatic determination of enclosure-related events may enable triaging and transmission of repair alerts to maintenance personnel.