In the field of measuring physical parameters with a multimode optical fiber, a system for measuring P physical parameters at one or more measurement points has one or more multimode optical fibers. The system includes: a light source generating a source optical signal, a multimode measurement optical fiber transporting optical signals in at least M distinct second predetermined propagation modes, M being an integer greater than or equal to P, the measurement optical fiber including a measurement section reflecting the optical signals with a wavelength variable according to physical parameters to be measured, a detection device measuring wavelengths of the optical signals reflected by the measurement section, and an optical module generating M signals from the source optical signal, the M signals each being injected into the measurement optical fiber to propagate in one of the modes, the optical module also transferring the optical signals reflected toward the detection device.

The invention relates to a device and method for detecting an acoustic wave propagating toward a membrane, the membrane carrying a waveguide comprising an optical cavity defining a resonant frequency. Under the effect of a vibration of the membrane, the resonance frequency of the optical cavity varies. The device includes a light source for directing a light wave into the optical cavity, and a servo circuit for servo-controlling the wavelength of the light wave to the resonant wavelength of the optical cavity. Monitoring the variation in the wavelength of the light wave allows an amplitude of the acoustic wave to be estimated.

A system includes a sensor network comprising at least two optical fibers coupled to a pavement. Each optical fiber includes one or more optical sensors installed a predetermined distance from one or more adjacent optical fibers. The one or more optical sensors are configured to produce a wavelength shift signal. A processor is configured to determine one or both of one or more attributes of one or more objects travelling on the pavement and a traffic condition of the pavement based on the wavelength shift signal. A transmitter is configured to transmit the one or more attributes to a predetermined location.

One or more spacers for installing an optical cable are disposed in a trench that extends along an axis. The optical cable includes one or more optical sensors. Each spacer includes a base configured to rest in a bottom of the trench. A first arm extends from the base. The first arm is adjacent to a first wall of the trench. An opposing second arm extends from the base. The second arm is adjacent to an opposing second wall of the trench. The optical cable is configured to extend along the axis.

A fiber optic sensor for detecting an excitation in proximity to a fiber optic assembly, the excitation inducing a modulation of the phase of an optical signal propagating in the fiber optic assembly, the sensor comprises: a laser assembly emitting at least one laser beam; a fiber optic assembly; an optical system configured to: inject at least one portion of the laser beam; generate at least one laser signal beam issued from the laser beam injected into and propagated in the fiber assembly; generate at least one reference beam from the laser beam or the signal beam; produce at least one interference zone corresponding to the interference between a portion of the reference beam and a portion of the interference signal beam corresponding to the interference between a portion of the reference beam and a portion of the signal beam; a digital holography assembly comprising: a liquid-crystal spatial light modulator; a video camera configured to receive the interference zone and to transcribe it electrically to the liquid-crystal spatial light modulator in order to create thereon a phase hologram corresponding thereto; at least one optical detector configured to detect an output optical signal beam.

A Bragg grating optical fiber sensor for measuring temperatures and deformations and a method for manufacturing same, the manufacturing method including ablating a mechanical coating over a portion of an optical fiber so as to form an opening extending radially over the entire thickness of the mechanical coating, and inscribing a Bragg grating into the optical fiber through the opening.

A system includes a first and second sensor for a first and second body portion, wherein each sensor includes perturbation sensors for determining physical perturbations for each respective body portion in response to a body movement, each sensor includes a processor for determining orientation and velocity data for each respective body portion in response to the physical perturbations, a shape sensing unit coupled to a joint portion between the first and second body portions including an optical fiber configured to bend in response to the body movement, a light source for providing light into the optical fiber, a light sensor for sensing reflected light from the optical fiber in response to being bent, and a processor for determining curvature data associated with the joint portion, and a central processor for determining user movement data in response to the orientation and velocity data for each body portion and the curvature data.

A method for producing a glass furnace, including a refractory portion, a waveguide with a measurement portion extending into the refractory portion and an interrogator connected to an input of the waveguide to inject an interrogation signal. The measurement portion incorporating a sensor to send a response signal to the interrogator in response to the injection. The interrogator analyzing the response signal and sending a message. Arranging, inside a mold, a temporary part configured to leave space for a compartment for the measurement portion. Preparing a starting feedstock and introducing the starting feedstock into the mold such that the part is embedded therein to obtain a preform. Hardening the preform to form the refractory portion. Removing the temporary part to make the compartment. Assembling the refractory portion with other constituent elements and introducing the measurement portion into the compartment and connecting the interrogator to the input of the waveguide.

A fiber Bragg grating (FBG) security component for single-party and multi-party monitoring is provided. The security component includes an optical fiber having a plurality of Bragg gratings. The Bragg gratings provide a spectral response that is randomized based on the manufacture of the security component. For single-party use, the spectral response provides a reproducible spectral signature when interrogated with an optical signal. For multi-party use, each party applies a known optical interrogation signal to the security component and applies an external stress known only to the respective monitoring party. The resulting shift in the spectral signature is unique to each monitoring party, making it extremely difficult to successfully counterfeit the security component's response for all such parties.

A medical device that includes a carrier member, one or more operative components disposed in the carrier member, an optical fiber at least partly disposed in the carrier member, and at least one fiber Bragg grating (FBG) sensor array associated with the optical fiber and disposed in the carrier member. The carrier member includes an insertion end and side walls that contact the subject's body during positioning of the carrier member in the subject's body. The at least one FBG sensor array measures contact forces at one or both of the insertion end and along the side walls of the carrier member during positioning of the carrier member in the subject's body. A multi-core optical fiber configured for use in a medical device for positioning in a subject's body is also provided. A system and method for guiding positioning of a medical device in a subject's body is also provided.