Thales

Gerard Roux

Martine Doisy

Raphael Lardat

Sylvie Ponthus

Francois-Xavier Launay

The invention consists of an optical hydrophone, an optical fiber element forming a laser cavity, housed in a mechanical structure which comprises an open cylindrical rigid body, defining the cavity enclosing a fluid and in which the optical fiber element is housed, and closed at its ends by two end caps which keep the optical fiber element permanently under tension, in a longitudinal rectilinear position inside the cavity. The end caps are configured in such a way that when the exterior pressure varies, they undergo a deformation giving rise to a variation in the length of the optical fiber element and that when the temperature varies, they undergo a deformation giving rise to a variation in the length of the optical fiber element which compensates for that induced on this element by the temperature variation. The mechanical structure furthermore exhibits one or more orifices allowing equilibration of the static pressures.

All-optical hydrophone insensitive to temperature and to static pressure

The present invention relates to a process for producing a block of low-frequency piezoelectric composite material having rows of superposed ceramic posts embedded in a dielectric. This process includes the production of the block of composite material from two superposed identical half-blocks, produced by cutting into a single pre-machined piezoelectric ceramic block. According to the invention, the block of ceramic material thus constituted is then machined so as to form a structure comprising rows of aligned posts, each post being formed from two elementary posts facing each other in strict alignment. The ceramic structure thus produced is then integrated into an appropriate dielectric matrix. The block thus produced is intended to be used for manufacturing acoustic transducers from composite materials. The invention relates in particular to the field of sonar detectors designed to detect objects located at a relatively short distance from the detector.

Growing community of inventors

Opio, France

Gerard Roux