Abstract: This invention relates to a laser cavity with passive triggering by saturable absorbent and with controlled polarization, and to a laser and in particular to a microlaser containing the said cavity and means of pumping this cavity. The invention also relates to a process for manufacturing the said microlaser. The laser cavity with controlled polarization comprises a substrate made of Y3Al5O12 (YAG) active laser material that may or may not be doped, on which a monocrystalline layer of saturable absorbent doped YAG material is deposited directly by liquid phase epitaxy or by a similar process, in which the said active laser material has a [100] orientation, and in which the said monocrystalline layer of saturable absorbent material is deposited with the same [100] orientation.

Abstract: Optically pumped laser minicavity, its production process and laser using said cavity, wherein the minicavity comprises an electrically insulating, parallelepipedic, solid emitter (1b), having two polished parallel lateral faces (6, 8), a monocrystalline substrate (2) and several monocrystalline layers epitaxied on the substrate and having in directions parallel to said faces a hardness equal to that of the substrate, one of the layers constituting a guide layer (4) able to guide the light emitted by the emitter and the pumping light and another layer (12) constituting a non-guiding protective layer, the protective layer and the substrate constituting two opposite faces of the emitter perpendicular to the lateral faces, laser activating ions being contained within the substrate and/or in one of the layers. In the case of an internal cavity, semi-reflecting mirrors (9, 10) are placed on the lateral faces of the emitter.

Abstract: The present invention relates to a capacitive hygrometer comprising a capacitor (1) having a dielectric material (3), whose dielectric constant varies as a function of the quantity of water absorbed. It has on one of its conductive faces numerous fissures bringing the dielectric material into direct contact with the atmosphere whose degree of humidity is to be measured. However, the electrical continuity of the fissured conductive face is maintained.Application to the measurement of the degree of humidity of the air.

Abstract: The present invention relates to a capacitive hygrometer comprising a capacitor (1) having a dielectric material (3), whose dielectric constant varies as a function of the quantity of water absorbed. It has on one of its conductive faces numerous fissures bringing the dielectric material into direct contact with the atmosphere whose degree of humidity is to be measured. However, the electrical continuity of the fissured conductive face is maintained. Application to the measurement of the degree of humidity of the air.