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 optical inspection system includes an optical fiber sensor, an optical filter, a signal processor, and a corrector. The optical fiber sensor outputs a first optical signal having a temporal change in a wavelength corresponding to a temporal change in an amplitude of a vibration propagating in an inspection target object or a temporal change in a displacement of the inspection target object. The optical filter converts the first optical signal into a second optical signal having a temporal change in an intensity. The signal processor acquires inspection information on the inspection target object on the basis of the second optical signal. The corrector corrects a correspondence relationship between the temporal change in the wavelength and the temporal change in the intensity by changing a wavelength characteristic of the optical filter. The correspondence relationship is directed to converting the first optical signal into the second optical signal.

Light receiver includes first optical element emitting received light to a light receiving fiber side; and second optical element collecting the light incident from the first optical element on a light receiving fiber. First optical element includes prism surface inclined with respect to light incident surface. The prism surface includes first surface 4a reflecting the incident light parallel to the light incident surface and second surface reflecting the light on a side opposite to the second optical element. The first surface includes first region in which the light reflected in parallel to the light incident surface is incident on the second optical element, and second region in which the light reflected in parallel to the light incident surface transmits through the adjacent second surface, is incident and refracts on the adjacent first surface, and is incident on the second optical element while being totally reflected inside the first optical element.

In order to enable an area suspected of having a communication abnormality to be identified from among a communication device and a communication path that constitute a communication system, this abnormality identification device is provided with: a first output unit which outputs first information that is information indicating the suitability of a transmission signal to be supplied to a communication channel; a second output unit which outputs second information that is information indicating the suitability of a reception signal corresponding to the transmission signal that has arrived via the communication channel; and a third output unit which outputs third information that is information indicating the suitability of a signal obtained by applying predetermined processing to the reception signal.

This application relates to methods and apparatus for monitoring power cables (100) carrying multiple AC phases to detect deformation of the power cable. A distributed fibre optic interrogator unit (302) is used to interrogate a sensing optical fibre (301) coupled to the power cable to provide a measurement signal from each of a plurality of longitudinal sensing portions of the sensing optical fibre. An analyser (602) is configured to analyse the measurements signals to detect a characteristic of an imbalance in magnetic fields. The characteristic may be a signal component with a characteristic frequency related to the power frequency and number of AC phases, the sensing optical fibre may be sensitised to magnetic fields and the characteristic frequency may be 2n times the power frequency where n is the number of phases, e.g. six times the power frequency for three phase AC.

A wading structure health sensing distributed optical fiber calibration system and a method includes a heat insulation barrel, and calibration modules located in the inner ring of the barrel, the calibration module comprises a through-shaft, a first electronic thermometer and a second electronic thermometer, an optical cable to be calibrated is twisted on the through-shaft and is connected to an optical fiber temperature demodulator outside the heat insulation barrel, the first and second electronic thermometers are respectively connected to first and second temperature control meters outside the barrel, a temperature source wire for heating water in the barrel arranged in the wall of the barrel, the temperature source wire connected to a power temperature control meter outside the barrel, and the first temperature control meter connected to cooling and heating devices simultaneously through leads of the first temperature control meter.

An optical fiber sensing system includes a sensing optical fiber and one or more optical amplifiers in series with the sensing fiber and arranged to increase the power of sensing pulses travelling along the fiber to thereby increase the range of the sensing system. The optical fiber sensing system is one selected from the group including an optical fiber distributed acoustic sensor (DAS), an optical fiber distributed temperature sensor (DTS), or an optical time domain reflectometry (OTDR) system.

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 optical sensor includes an optical device including a microresonator, laid out to guide a light beam along a closed loop optical path, and an injection and/or extraction waveguide, optically coupled to the microresonator; a photodetector, arranged at the output of the injection and/or extraction waveguide; and an analysis device, receiving a signal supplied by the photodetector, and deducing therefrom information relative to a displacement. The microresonator is constituted of a plurality of elementary waveguides spaced apart from each other, and arranged one after the other according to a loop shaped layout. The optical sensor offers increased sensitivity to the measurement of nanometric displacements.

An optical inspection system includes an optical fiber sensor, an optical filter, a signal processor, and a corrector. The optical fiber sensor outputs a first optical signal having a temporal change in a wavelength corresponding to a temporal change in an amplitude of a vibration propagating in an inspection target object or a temporal change in a displacement of the inspection target object. The optical filter converts the first optical signal into a second optical signal having a temporal change in an intensity. The signal processor acquires inspection information on the inspection target object on the basis of the second optical signal. The corrector corrects a correspondence relationship between the temporal change in the wavelength and the temporal change in the intensity by changing a wavelength characteristic of the optical filter. The correspondence relationship is directed to converting the first optical signal into the second optical signal.