A method of wrapping optical fiber around a fluid conduit. The optical fiber is wrapped at least partially around the conduit. The optical fiber is secured relative to the conduit at one or more securing locations, thereby defining a sequence of multiple optical fiber portions. Each optical fiber portion comprises a portion of the optical fiber. Each securing location delimits a given optical fiber portion from the subsequent optical fiber portion in the sequence of optical fiber portions. A direction of wrapping of each consecutive optical fiber portion in the sequence of optical fiber portions may be alternated between a clockwise direction and a counter-clockwise direction.

An optical fiber distributed acoustic sensor system makes use of a specially designed optical fiber to improve overall sensitivity of the system by a factor in excess of 10. This is achieved by inserting into the fiber weak broadband reflectors periodically along the fiber. The reflectors reflect 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%. To allow for temperate compensation to ensure that the same reflectivity is obtained if the temperature changes, the reflection bandwidth is relatively broadband. 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. The reflectors are spaced at the desired spatial resolution of the optical fiber DAS.

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.

An optical fiber sensing expansion apparatus (30) according to the present disclosure includes a sensor unit (32) storing a sensing optical fiber (33), a fixing unit for fixing the sensor unit (32) to a monitoring object (40), and a fiber connection unit (31) that is capable of connecting the sensing optical fiber (33) to an optical fiber (10), wherein the fiber connection unit (31) superimposes a detection result of the sensor unit (32) on an optical signal to be transmitted by the optical fiber (10).

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 untrained 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.

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 untrained 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.

An optical fiber distributed acoustic sensor system makes use of a specially designed optical fiber to improve overall sensitivity of the system by a factor in excess of 10. This is achieved by inserting into the fiber weak broadband reflectors periodically along the fiber. The reflectors reflect 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%. To allow for temperate compensation to ensure that the same reflectivity is obtained if the temperature changes, the reflection bandwidth is relatively broadband. 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. The reflectors are spaced at the desired spatial resolution of the optical fiber DAS.

An intelligent skin based on a small-size distributed optical fiber sensing array. The intelligent skin includes an epidermis sensing array, an embedded optical fiber sensing array, a data collection system module, and a data processing mode recognition module. The body of the intelligent skin is made of a flexible material. The embedded optical fiber sensing array in an epidermis includes a plurality of all-fiber interferomatic sensing arrays. The data collection system module includes a broadband light source, an optical combiner/splitter, an optical path change-over switch, a signal detector and a computer. The data processing mode recognition module includes mode recognition and training of a neural network. The intelligent skin further includes an external display software used to perform intelligent sensing recognition for sense of touch, position, shape, and ingredient, temperature and vibration of an object and so on.

An apparatus has a cassette configured to hold optical fiber comprising one or more optical sensors. The cassette has a spool configured to one or more of extract and retract the optical fiber from the cassette. A pre-strain mechanism is configured to apply a predetermined pre-strain to the one or more optical sensors. An optical fiber installation tool is configured to mount the optical fiber comprising the one or more pre-strained optical sensors to a surface.

An apparatus includes a cassette configured to hold optical fiber comprising one or more optical sensors. The cassette comprises a spool configured to one or more of extract and retract the optical fiber from the cassette. A fiber monitor is coupled to the cassette. The fiber monitor is configured to monitor at least one parameter of the optical fiber as the optical fiber is extracted from the cassette.