A sensor system includes a sensor network comprising at least one optical fiber having one or more optical sensors. At least one of the optical sensors is arranged to sense vibration of an electrical device and to produce a time variation in light output in response to the vibration. A detector generates an electrical time domain signal in response to the time variation in light output. An analyzer acquires a snapshot frequency component signal which comprises one or more time varying signals of frequency components of the time domain signal over a data acquisition time period. The analyzer detects a condition of the electrical device based on the snapshot frequency component signal.

A sensor system includes a sensor network comprising at least one optical fiber having one or more optical sensors. At least one of the optical sensors is arranged to sense vibration of an electrical device and to produce a time variation in light output in response to the vibration. A detector generates an electrical time domain signal in response to the time variation in light output. An analyzer acquires a snapshot frequency component signal which comprises one or more time varying signals of frequency components of the time domain signal over a data acquisition time period. The analyzer detects a condition of the electrical device based on the snapshot frequency component signal.

Disclosed herein is an optical cable comprising a support; flexible protective tubes helically wound around the support, each flexible protective tube comprising an optical fiber comprising an optical core; a cladding disposed on the core; and a primary coating external to the cladding; and a deformable material surrounding the optical fiber; an outer jacket surrounding the flexible protective tubes; wherein each optical fiber is about 0.5% to about 1.5% longer than its respective flexible protective tube; wherein an allowable strain on the optical cable with substantially zero stress on the optical fibers is determined by equations (1) and (2) below: $\begin{array}{c}\mathrm{.Math.}=\underset{\_}{\sqrt{{{\pi }^2\left(D+\frac{d}{2}\right)}^2+p^2}}\underset{}{\sqrt{{{\pi }^2(D-\frac{d}{2}}^{}}}\end{array}$

A sensing textile includes at least one assembly of optical fiber filaments, wherein the sensing textile has a main direction and a cross direction, and wherein the at least one assembly of optical fiber filaments is oriented at any angle measured relative to the cross direction.

An aircraft and method of operating an aircraft. The aircraft includes a temperature sensor and a processor. The temperature sensor that obtains an optical signal indicative of a temperature at a selected location of an outer surface of the aircraft. The processor is configured to determine the temperature at the selected location from the optical signal, and operate the aircraft based on the temperature at the selected location.

Aspects of the present disclosure describe optical fiber sensing systems, methods and structures disclosing a distributed fiber sensor network constructed on an existing, live network, data carrying, optical fiber telecommunications infrastructure to detect temperatures, acoustic effects, and vehicle trafficamong others. Of particular significance, sensing systems, methods, and structures according to aspects of the present disclosure may advantageously identify specific network locations relative to manholes/handholes and environmental conditions within those manholes/handholes namely, normal, flooded, frozen/iced, etc.

The present invention relates to an optical fiber sensor, comprising an optical fiber having embedded therein at least one fiber core (14, 16, 18, 20) extending along a length of the optical fiber, the at least one fiber core having a plurality of single fiber Bragg gratings (40, 42, 44) arranged in series along the at least one fiber core (14, 16, 18, 20), wherein each fiber Bragg grating (40, 42, 44) has a single reflection spectrum around a single reflection peak wavelength when interrogated with light in an unstrained state of the at least one fiber core (14, 16, 18, 20), wherein the reflection peak wavelengths of the single reflection spectra are different from fiber Bragg grating (40, 42, 44) to fiber Bragg grating (40, 42, 44) along the at least one fiber core. Also described is an optical system and a method of interrogating an optical fiber sensor.

A fiber optic sensor and a related method of manufacture are provided. The fiber optic sensor includes an embedded optical fiber contained within a metal diaphragm assembly, where the terminal end of the optical fiber is positioned opposite a diaphragm. The method includes forming a metal-embedded optical fiber by ultrasonic additive manufacturing and securing the metal-embedded optical fiber to a housing having a diaphragm that is opposite of the terminal end of the optical fiber. The sensor can provide extremely accurate pressure measurement at high temperatures and in highly corrosive media. An optical fiber-based pressure sensing system is also provided.

Disclosed are systems and methods for a self-monitoring conducting system that can respond to temperature, strain, and/or radiation changes via the use of optical fibers. The self-monitoring conducting system comprises a conducting component integrated with one or more optical fibers. The temperature, strain, and/or radiation changes can be sensed or detected via optical interrogation of the one or more optical fibers.

An optical fiber distributed acoustic sensor system includes weak broadband reflectors inserted periodically along the fiber. The reflectors reflect only a small proportion of the light from the DAS incident thereon back along the fiber, typically in the region of 0.001% to 0.1%, but preferably around 0.01% reflectivity per reflector. In addition, to allow for temperate compensation to ensure that the same reflectivity is obtained if the temperature changes, the reflection bandwidth is relatively broadband. In some embodiments the reflectors are formed from a series of fiber Bragg gratings, each with a different center reflecting frequency, the reflecting frequencies and bandwidths of the gratings being selected to provide the broadband reflection. A chirped grating may also be used to provide the same effect. In preferred embodiments, the reflectors are spaced at half the gauge length i.e. the desired spatial resolution of the optical fiber DAS.