Abstract: A compact optical coupling device particularly adapted for coupling between a source and two optical fiber ends having a function of separation of the radiation from the source between these two ends. The device comprises a small-size separator cube, a plano-convex microlens whose flat face is bonded to the input face of the separator cube, and two square-section end-pieces bonded to the two output faces of the separator cube, each enclosing one fiber end.

Abstract: An interferometric gyrometer using a laser source and beam separator forming two waves each directed to one end of a wound monomode fiber and recombined after passage. A permanent phase shift equal to .pi./2 is introduced between the two waves emerging from the ends of the fiber, and a switch is alternately shifted between a state transmitting the recombined waves and a state inverting the phase of the recombined waves. A synchronous demodulator, receiving the detected and amplified signal and a signal synchronous with the control signal applied to the switch supplies a signal proportional to the speed of rotation of the gyrometer.

Abstract: A laser gyrometer for the measure of the angular speed of a rotating system, comprising an optical fiber wound around the rotation axis, in which two coherent light beams are guided in the direction of the rotation and in the opposite direction, respectively, so as to be subjected to the Sagnac effect. The two beams emerging from the two ends of the fiber are directed along two separate adjacent parts of one beam. Measurement of the phase shift between the two parts is based on the displacement of the center of the diffraction spot obtained in the focal plane of a lens, positioned in the path of the beam.

Abstract: A high-precision mask photorepeater projects the image of a mask upon a sample. The sample upon which an impression is to be made is a thin plate of semiconductor material with dimensions of the order of 10 centimeters. Each zone to be recorded is brought opposite the lens. A system of pneumatic sensors brings the center of the zone to be recorded into the correct plane and positions this zone in the focal plane of the lens.