Thomson-csf

Serge Botti

Herve Lefevre

Jean P Bettini

Marc Turpin

Herve J Arditty

Philippe Graindorge

Didier Rolly

Jean-Pierre Bettini

Electromagnetic disturbance free ring interferometer

A spool for optic fibers and its winding method are disclosed. The cylinder of the spool has grooves in which rods are placed during the winding operation. Thus, the circumference of the spool is greater than that of the cylinder. After winding, the rods are removed so that the winding stresses are relaxed.

Spool for optic fiber and method for winding without stress on optic

A multiple-point temperature sensor, with optic fibers, uses the effect of variation in the birefringence in a birefringent optic fiber as a function of temperature. This sensor has a plane polarized, wide spectrum source coupled to a monomode optic fiber for preservation of polarization, along one of the neutral axes, with weak coupling points distributed along this fiber. A polarizer at 45.degree. to the neutral axes of the fiber is placed at the output of this sensing fiber. The output radiation is analyzed by spectroscopy, for example in a Michelson interferometer, capable of being swept, associated with a detector. The interferometer shifts needed to detect the extreme values of the transmission function are measurements of temperature deviations.

Multiple-point temperature sensor using optic fibers

A method for the detection of localized polarization couplings in a birefringent guided optical system uses a polarizer, at 45.degree. with respect to the axes of the optical system placed at its output, and followed by a Michelson type interferometer in which one of the optical paths has a variable length. When the length of an optical path undergoes variation, interference fringes appear on half of the energy emitted. The difference in the length of the optical paths when fringes of this type appear characterizes the position of a localized polarization coupling, and the contrast between the fringes measured for this difference in length characterizes the amplitude ratio between the primary wave and the coupled wave. The invention can be applied in particular, to the assembly of the components of a birefringent optical system.

Method for the detection of polarization couplings in a birefringent

A method of coiling an optical fiber gyroscope and an optical fiber coil thus obtained, which method consists in coiling, on a cylindrical support comprising a central channel, a first layer for forming a helical optical fiber winding with constant pitch, passing the optical fiber through the central channel in the form of a single turn and coiling additional layers, in the same direction as the first layer, using the interturn spaces of the underlying layers.

Growing community of inventors

Viroflay, France

Serge Botti