A digital measuring device implemented on a photonic integrated circuit, the digital measuring device including a tunable laser source implemented on the photonic integrated circuit configured to sweep over a frequency range to provide multi-wavelength light, a first waveguide structure implemented on the photonic integrated circuit configured to direct a first portion of light from the laser source at a moving object and receive light reflected from the moving object, a second waveguide structure implemented on the photonic integrated circuit configured to combine a second portion of light from the laser source with the light reflected from the moving object to produce a measurement beam, and a first detector implemented on the photonic integrated circuit configured to detect intensity values of the measurement beam to measure a distance between the digital measuring device and the moving object.

A multiple sensor fiber optic sensing system includes an optical fiber having at least first fiber optic sensors and second fiber optic sensors deployed along its length. In response to an interrogating pulse, the first fiber optic sensors generate responses in a first optical spectrum window, and the second fiber optic sensors generate responses in a second, different optical spectrum window. The responses in the first optical spectrum window are measured in a first optical spectrum channel, and the responses in the second optical spectrum window are measure in a second, different optical spectrum channel and provide simultaneous indications of one or more parameters, such as temperature and pressure, in the environment in which the sensors are deployed.

A system (10) includes an optical source, multiple coupler units (22), a controller (20), and a detector (123). The optical source is configured to transmit an optical signal into an optical cable (40). The multiple coupler units are coupled to the optical cable and are each configured to (i) accept one or more configuration parameters, (ii) receive data from one or more sensors (30), (iii) modulate the data onto an acoustical signal in accordance with the configuration parameters, and (iv) modulate a mechanical strain applied to the optical cable with the acoustic signal, so as to modulate the optical signal with the data. The controller is configured to coordinate and send the configuration parameters to the multiple coupler units. The detector is configured to receive the optical signal from the optical cable, and to demodulate the data that was modulated onto the optical signal by the multiple coupler units.

A digital measuring device implemented on a photonic integrated circuit, the digital measuring device including a laser source configured to provide light, a first ring resonator configured to produce a first frequency comb of light from the laser source, wherein at least a portion of the first frequency comb of light is directed at a moving object, a local oscillator configured to provide a reference beam, at least one waveguide structure configured to combine the reference beam with light reflected from the moving object to produce a measurement beam, a first multiplexer configured to split the measurement beam into a plurality of channels spaced in frequency, and a plurality of detectors configured to detect an intensity value of each channel of the plurality of channels to measure a distance between the digital measuring device and the moving object.

The invention relates to a system and method for detecting vibrations on the periphery of an optical fibre, which is divided into five subsystems that are connected together. First, a light-source subsystem (6) generates light, which is transmitted through an optical fibre subsystem (2). Then, speckle interference patterns generated in the optical fibre are read using a CMOS micro camera subsystem (5). Subsequently, the information is analysed by a processing subsystem (7), producing an alarm signal that is notified to the outside by means of a communications subsystem (1).

A digital measuring device implemented on a photonic integrated circuit, the digital measuring device including a tunable laser source implemented on the photonic integrated circuit configured to sweep over a frequency range to provide multi-wavelength light, a first waveguide structure implemented on the photonic integrated circuit configured to direct a first portion of light from the laser source at a moving object and receive light reflected from the moving object, a second waveguide structure implemented on the photonic integrated circuit configured to combine a second portion of light from the laser source with the light reflected from the moving object to produce a measurement beam, and a first detector implemented on the photonic integrated circuit configured to detect intensity values of the measurement beam to measure a distance between the digital measuring device and the moving object.

A method and a system for interrogating an optical fiber includes a probe signal that has a first frequency comb at a first repetition rate (Δf) injected into the optical fiber. A backscattering signal that includes the probe signal convolved with an impulse response of the optical fiber in reflection which is sensitive to at least one parameter being measured from the optical fiber is gathered. The backscattering signal is beaten with a local oscillator signal to generate a beating signal, the local oscillator signal including a second frequency comb at a second repetition rate that is offset from the first repetition rate (Δf+δf) and being mutually coherent with the first frequency comb. The resulting beating signal is analysed to thereby determine the at least one parameter being measured from the optical fiber.

A digital measuring device implemented on a photonic integrated circuit, the digital measuring device including a laser source configured to provide light, a first ring resonator configured to produce a first frequency comb of light from the laser source, wherein at least a portion of the first frequency comb of light is directed at a moving object, a local oscillator configured to provide a reference beam, at least one waveguide structure configured to combine the reference beam with light reflected from the moving object to produce a measurement beam, a first multiplexer configured to split the measurement beam into a plurality of channels spaced in frequency, and a plurality of detectors configured to detect an intensity value of each channel of the plurality of channels to measure a distance between the digital measuring device and the moving object.

A distributed sensing apparatus based on Optical Time Domain Reflectometry, OTDR, including an optical source; an optical splitter in optical communication with the optical source, the optical splitter having first and second outputs; a sensing fibre in optical communication with the first output of the optical splitter; a combining unit arranged to combine a reference signal derived from the second output of the optical splitter with a backscattered signal derived from the sensing fibre, wherein the combining unit comprises one or more 3×3 fused fibre couplers; and a signal processing unit configured for processing information derived from the combining unit so as to provide distributed sensing data. The combining unit includes a polarization diversity arrangement including one or more polarization sensitive elements.

A reflected light wavelength scanning device having a silicon photonics interrogator is provided. The device includes: a light source module for outputting broadband light; an optical sensor that receives light output from the light source module through a circulator, reflects light in a specific band to the circulator, and transmits light in a band other than the specific band; and an interrogator for selectively injecting the polarized light by separating the polarized light from the reflected light input through the circulator.