Abstract: Method for obtaining an organic polycrystalline material having in particular electro-optical properties, said material obtained and an electro-optical modulator comprising said material. This method includes a stage (1) for preparing a powder having a size grading of 500 to 800 nm of an organic compound having a delocalized system of .pi. electrons and presenting a non-centrosymmetrical crystalline structure, as well as intramolecular load transfer groupings, a stage (2) for drying the powder under vacuum, a stage (3) for pre-pressing the powder under vacuum, and a hot stage (5) for the uniaxial compression of the dried powder under vacuum. This method enables polycrystalline materials to be obtained, said materials comprising elongated monocrystalline grains orientated according to a given direction.

Abstract: A superconducting screen printing ink comprises an organic composition, a mineral binder and a mineral composition which is a high temperature superconducting Bi-Sr-Ca-Cu-O material or a precursor therefore. A thick superconducting film is produced by screen printing deposition of the ink on a substrate through a mask, drying and then baking the deposited ink. The ink and film are useful in microelectronics.

Abstract: Method for obtaining an organic polycrystalline material having in particular electro-optical properties, said material obtained and an electro-optical modulator comprising said material.This method includes a stage (1) for preparing a powder having a size grading of 500 to 800 nm of an organic compound having a delocalized system of electrons .pi. and presenting a non-centrosymmetrical crystalline structure, as well as intramolecular load transfer groupings, a stage (2) for drying the powder under vacuum, a stage (3) for pre-pressing the powder under vacuum, and a hot stage (5) for the uniaxial compression of the dried powder under vacuum.This method enables polycrystalline materials to be obtained, said materials comprising elongated monocrystalline grains orientated according to a given direction.

Abstract: Process for depositing and crystallizing a thin layer of organic material by means of a beam of energy.A compact block formed of organic material is disposed adjacent one of the faces of the substrate, the block is subjected through the substrate to the action of a laser beam, so as to desorb the organic material forming the block, the substrate being optically transparent to the beam, and a relative displacement is performed between the substrate and the beam in order to sweep such faces over a given path, to enable the desorbed material to be deposited on the face of the substrate opposite the block, and the material thus deposited to be crystallized in a quasi-crystalline form.Application to the manufacture of integrated optical products, such as lenses, mirrors, networks and the manufacture of opto-electronic components.

Abstract: The invention relates to a novel oxide for tunable lasers. These oxides comply with the formula:(A.sub.1-x X.sub.x).sub.n (B.sub.1-y Y.sub.y).sub.m O.sub.4in whichA represents one or more elements chosen from the group Mg, Mn and Zn;X represents one or more optically active divalent cations chosen from among V, Ni and Co;B represents one or more elements of the same valence chosen in the group comprising Si, Ge, P, Te, W, Al, In, Ga and Mo;Y represents one or more optically active trivalent cations chosen from among Cr, V and Ni;x is such that 0.ltoreq.x.ltoreq.0.15;y is such that 0.ltoreq.y.ltoreq.0.15; andm and n are integers such that 2n+vm=8 with v representing the valence of B, provided that y=0 when B represents one or more elements chosen from among Si, Ge, P, Te, W and Mo and x and y are not both equal to 0.As an example of such oxides, reference is made to Mg.sub.0.99 Ni.sub.0.01 Al.sub.2 O.sub.