A system may include a substrate, a computing device that performs one or more edge processing operations disposed on the substrate, and an integrated photonic circuit that performs distributed acoustic sensing operations and is also disposed on the substrate. The integrated photonic circuit may include a light source, a circulator, and a photodiode. The light may transmit a first light pulse. The circulator may transmit the first light pulse to a fiber-optic cable. The circulator may also receive a back-scattered light pulse based at least in part on the first light pulse. The photodiode may receive at least a portion of the back-scattered light pulse. The photodiode may generate one or more electrical signals based at least in part on the portion of the back-scattered light pulse.

A sensor comprises: a thin structure, which is configured to receive a force for deforming a shape of the thin structure and which is arranged above a substrate; and a waveguide for guiding an electro-magnetic wave comprising: a first waveguide part; and a second waveguide part; wherein the second waveguide part has a larger width than the first waveguide part; and wherein the first and the second waveguide parts are spaced apart by a gap which is sufficiently small such that the first and second waveguide parts unitely form a single waveguide, wherein one of the first and the second waveguide part is arranged at least partly on the thin structure and another of the first and the second waveguide part is arranged on the substrate.

A waveguide for guiding an electro-magnetic wave comprises: a first waveguide part; and a second waveguide part; wherein the first waveguide part has a first width in a first direction (Y) perpendicular to the direction of propagation of the electro-magnetic wave and the second waveguide part has a second width in the first direction (Y), wherein the second width is larger than the first width; and wherein the first and the second waveguide parts are spaced apart by a gap in a second direction (Z) perpendicular to the first and second planes in which the waveguide parts are formed, wherein the gap has a size which is sufficiently small such that the first and second waveguide parts unitely form a single waveguide for guiding the electro-magnetic wave.

A photonic integrated circuit component, a sensor and an actuator comprising the waveguide are disclosed.

A system may include a substrate, a computing device that performs one or more edge processing operations disposed on the substrate, and an integrated photonic circuit that performs distributed acoustic sensing operations and is also disposed on the substrate. The integrated photonic circuit may include a light source, a circulator, and a photodiode. The light may transmit a first light pulse. The circulator may transmit the first light pulse to a fiber-optic cable. The circulator may also receive a back-scattered light pulse based at least in part on the first light pulse. The photodiode may receive at least a portion of the back-scattered light pulse. The photodiode may generate one or more electrical signals based at least in part on the portion of the back-scattered light pulse.

Local strain and optionally other properties of an optical sensing fiber are detected as a function of position along the optical sensing fiber. A light pulse with a plurality of simultaneous laser modes at mutually different wavelengths is transmitted into the optical sensing fiber. Light produced by backscattering of the light pulse in the optical fiber is fed to a multi-way coupler, via a first and second optical path with different optical path lengths. Intensities of different phase combinations of light from the paths are detected by detectors at the outputs of the multiway coupler. A data processing system computes relative phase values of light from the first and second paths for a series to time points with time delays corresponding to scattering at different positions along the fiber. In an embodiment, inelastically scattered light such as due to Brillouin scattering and/or Raman scattered light is selective passed to the detectors and detected.

A system and method for determining an object characteristic from a timed sequence of measured characteristics wherein the object characteristic is determined based on a comparison of a current measured characteristic against a variable reference characteristic. The variable reference characteristic is selected by iterating through the timed sequenced and determining a separate quality metric for the current measured characteristic against each earlier measured characteristic and selecting the variable reference as a function of the determined quality metrics. In one embodiment, iteration continues only until an earlier measured characteristics is found with a quality metric that meets or exceeds a threshold value. In another embodiment, iteration continues through a plurality of earlier measured characteristic (perhaps all) and the variable reference is selected as the earlier measured characteristic with the highest quality metric. The measured characteristics may include OFDR measurements.

An interferometric demodulation system for a large capacity fiber grating sensing network is provided by the present disclosure, comprising: a continuous light output end of the nanoscale wide-spectrum light source is connected to an input end of the pulse optical modulator, an output end of the reference grating is connected to an input end of the grating array sensing network, and a third communication end of the optical circulator is connected to an input end of the optical amplifier, an output end of the optical amplifier is connected to an input end of the Mach-Zehnder interferometer, three-channel signal output ends of the Mach-Zehnder interferometer are respectively connected to signal input ends corresponding to the embedded signal processor through the photoelectric converter, and the embedded signal processor controls the heating device to control a temperature of an any one of interference arms of the Mach-Zehnder interferometer.

Disclosed are a system and a method for measuring a magnetorefractive effect of an optical fiber. The system comprises a laser, a coupler A, a sensing optical fiber, a reference optical fiber, a carrier generator, a coupler B, a photoelectric detector and a data acquisition and processing module. The coupler A, the sensing optical fiber, the reference optical fiber and the coupler B form a Mach-Zehnder optical fiber interferometer. An external magnetic field influences the refractive index of the sensing optical fiber, so that the optical path difference between two paths of optical signals in the sensing optical fiber and the reference optical fiber is changed, the intensity of an interference optical signal output by the coupler B is changed, and the refractive index change of the sensing optical fiber under the action of the magnetic field is measured by detecting and processing the interference optical intensity.

The present invention discloses a distributed device for simultaneously measuring strain and temperature based on optical frequency domain reflection, comprising a tunable laser, a 1:99 beam splitter, a main interferometer system, a light source phase monitoring system based on an auxiliary interferometer, an acquisition device and a computer processing unit, wherein the main interferometer system comprises two Mach-Zehnder interferometers, and two optical fibers having different cladding diameters are arranged in parallel as sensing fibers. Due to the difference in temperature and strain coefficients of optical fibers of the same diameter, the temperature and strain values during changing the temperature and strain simultaneously can be obtained by matrix operation, thereby achieving an effect of eliminating cross sensitivity of temperature and strain sensing in optical frequency domain reflection.

A distributed optical fiber disturbance positioning system based on the asymmetric dual Mach-Zehnder interference, unlike traditional dual Mach-Zehnder distributed optical fiber disturbance sensing system, the present invention adopts two narrow-bandwidth optical sources (1a, 1b) and adopts corresponding DWDM (3a, 3b) before the detector (4a, 4b) to filter the backscatter noise of the optical fiber, and can solve the problems of having too low SNR due to backscatter influence when the sensing distance is long. The present invention also provides a positioning method for applying the system, which obtains the TFD of the disturbance frame signals by using the time-frequency analysis method based on the short-term average frequency, and takes the points near the point of maximum frequency as the effective signal segment for performing cross-correlation time delay estimation, thus obtaining the delay, and the disturbance position. The method of the invention positions the asymmetric disturbance frame signals in the systems, thus having a high positioning accuracy and reliability.