Ixblue

Frederic Guattari

Herve Lefevre

Cedric Molucon

Eric Ducloux

Sebastien Ferrand

Stephane Chouvin

Jean-Jacques Bonnefois

Joachin Honthaas

Pascal Simonpietri

Alain Claire

Disclosed is a method for producing an optical fiber coil including the following steps: a. symmetrical winding of an optical fiber around a shaft, the winding forming a pattern including a same number N of layers of each half of the optical fiber, one layer including a set of turns of optical fiber and spaces between adjacent turns, the winding forming a sectored arrangement including a regular stacking area including at least one continuous sealing surface between two layers of adjacent turns, and an overlap area where portions of optical fiber linking different turns cross each other; b. infiltration of a glue through an external surface of the overlap area in such a way that the glue infiltrates into the spaces located between adjacent turns in the regular stacking area.

Method for producing an optical fiber coil, optical fiber coil and optical fiber interferometer

Interferometric measurement device includes a light source emitting a source signal and optical coupling elements receiving the source signal, directing part of the latter towards a measurement pathway including a Sagnac ring interferometer, of frequency f, producing a power output signal Ppolarized according to a first polarization direction, tapping off another part of the source signal towards a compensation pathway producing a return power compensation signal P, and directing the output and compensation signals towards detection elements. The compensation pathway includes polarization rotation elements producing the compensation signal according to a second cross-direction of polarization, and optical looping elements redirecting part of the compensation signal towards the measurement pathway; the detection elements include a single detector connected to the coupling elements for receiving the output signal and the compensation signal; the device further includes power equilibration elements equalizing the output power and/or return power are routed towards the detector.

Interferometric measurement device

An interferometric system with multi-axis optical fiber and a method for processing an interferometric signal in such a system, the multi-axis interferometric system includes a light source (); a plurality of N optical-fiber coils (), a first optical separation element () capable of splitting the source beam () into a first split beam () and a second split beam (); shared phase-modulation element (); a photodetector () and a signal-processing system (). The N optical-fiber coils () are connected in parallel, the coils having respective transit times T, T, . . . TN that all differ from one another, and the signal-processing system () is capable of processing the interferometric signal () detected by the shared photodetector () as a function of the respective transit times in the various coils.

Interferometric system with multiaxial optical fibre and method for processing an interferometric signal in such a system

A fiber-optic measurement device () includes a SAGNAC ring interferometer () having a proper frequency f, a detector () and a modulation chain () generating a phase-shift modulation &#x3c6;(t) between the two counter-propagating waves () propagating in the ring interferometer. The device aims to reduce measurement faults due to the linearity defects in the modulation chain of such a measurement device with optical fiber. For this reason, the fiber-optic measurement device reduces the amplitude of the phase-shift modulation &#x3c6;(t) which is the sum of a first biasing phase-shift modulation component &#x3c6;(t) and a first counter-reaction phase-shift modulation component &#x3c6;(t), the phase-shift modulation &#x3c6;(t) falling or rising by twice the amplitude of the first biasing phase-shift modulation component &#x3c6;(t). A rate gyro including such a measurement device and an inertial stabilization or navigation unit including at least one such rate gyro are also described.

Fibre-optic measurement device, rate gyro, and inertial stabilisation and navigation unit

A fiber-optic interferometric measurement device () intended to measure a physical parameter (QR), includes: a wide-spectrum light source (); a SAGNAC fiber-optic interferometer (), in which there propagate two counter-propagating light waves () including measurement elements () sensitive to the physical parameter that results in a non-reciprocal phase difference &#x394;&#x3c6;&#x3c1; between the two light waves; and a detector () delivering an electric signal representative of the physical parameter. The measurement elements include a ring resonator () in transmission mode including a first coupler () and a second coupler () respectively, which couple a first arm () and a second arm () respectively of the SAGNAC interferometer to the ring resonator, in such a way that the two light waves travel in opposing directions of travel (H,AH).

Fibre-optic interferometric measurement device comprising a ring resonator, gyrometer and inertial attitude or navigation unit comprising such a device

A fiber optic interferometric measurement system includes a light source; first and second optical transmission elements; first and second Sagnac-ring interferometers, respectively, including first and second fiber optic coils, and, respectively, having lengths Land L; and first and second individual integrated optical circuits, respectively, connected to the first and second optical transmission elements, and to the two ends of the first and second optic coils, respectively. The interferometric system includes a multiple integrated optical circuit integrating, on a single substrate, the first and second individual integrated optical circuits, and the difference &#x394;l between the optical length of the first optical transmission elements and the optical length of the second optical transmission elements is higher than the maximum of &#x394;Nb&#xd7;Land &#x394;NB&#xd7;L, in which &#x394;Nband &#x394;Nb, respectively, are the group birefringence index difference of the first and second fiber optic coils, respectively.

Interferometric measurement system with optical fibre and inertial guidance or navigation system including such an interferometric measurement system

An integrated optical circuit includes an optically transparent substrate including: an input face, an output face, an upper face and a lower face, the upper and lower faces extending between the input and output faces; at least one optical waveguide which includes at least one first end situated on the input face and a second end situated on the output face; and at least one optical attenuation zone able to attenuate an optical signal transmitted via the substrate to the outside of the waveguide. The waveguide has a non-rectilinear optical path between the first and second end, the attenuation zone extends from the upper face to the lower face, and is positioned on a straight line segment joining the first and second end of the optical waveguide, the waveguide and the attenuation zone having respective dimensions such that the attenuation zone does not cut the waveguide.

Integrated optical circuit with traversing attentuation zone

An integrated optical circuit includes a substrate having an input face, an output face, a lower face and an upper face, at least one optical waveguide having a first waveguide end located on the input face of the substrate and a second waveguide end located on the output face of the substrate. The lower face of the substrate includes a first part that is planar and parallel to the upper face and an optical block, the optical block being positioned in the median plane and in the incidence plane, the optical block forming a protrusion at least at the primary reflection point of the integrated optical circuit with respect to the first planar part of the lower face and the optical block being capable of receiving and attenuating at least one non-guided optical beam propagating on the optical path of a primary reflection.

Attenuated primary reflection integrated optical circuit

An integrated optical circuit includes a substrate having an input face, an output face, a lower face and an upper face, an optical waveguide extending between a first end located on the input face of the substrate and a second waveguide end located on the output face of the substrate. The integrated optical circuit further includes at least one off-center groove, the off-center groove extending from the lower face to the inside of the substrate, the at least one off-center groove being located at a non-zero distance d from the median plane, the off-center groove replacing a central groove and the at least one off-center groove being capable of attenuating the non-guided optical beam transmitted by the substrate between the first end and the second end.

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Aubervilliers, France

Frederic Guattari