Abstract: The invention relates to a modular assembly comprising at least two modules to be assembled together and to be electrically interconnected when assembled for the purpose of conveying a microwave signal from an electronic circuit of one of the modules to an electronic circuit of the other module, said electronic circuits being disposed in respective packages. One of said electronic circuits includes at least one opto-electronic component that is optically connected to at least one optical fiber. Both packages are adapted to receive a microwave feedthrough having a central conductor whose axial ends come into contact with conductive tracks belonging to each of said electronic circuits, respectively.

Abstract: The present invention relates to a method of putting a lens on an optical fiber, the method comprising the steps of depositing a lens of elliptical section and in the form of a hyperboloid of revolution on the cleaved end of a polarization-maintaining fiber.

Abstract: An optical system comprising a monomode main optical fiber coupled to a phototransducer, by means of an assembly between the monomode optical fiber and the phototransducer, which assembly comprises, in succession: a piece of graded index multimode fiber, a piece of step index multimode fiber, and a microlens.

Abstract: The present invention relates to a method of preparing an optical fiber for optimum coupling with a phototransducer, comprising the following steps: cleaving an end surface on an optical fiber; and depositing a succession of convex lenses on said cleaved surface over the core of the fiber, the lenses being in axial alignment and of decreasing radii of curvature on going away from the fiber. The present invention also provides a system obtained by implementing the method.

Abstract: Optical spectroscope for scanning electron microscopes, the latter comprising a vacuum chamber containing a sample holder bombarded by an electron beam.The microscope chamber contains a concave mirror having an opening, a plane deviating mirror and an exit window for the chamber. Outside the microscope chamber is provided a drum carrying a plurality of flat diffractive gratings, the drum being equipped with a bracket which rotates about an axis controlled by a stepping motor. In addition there are a spherical concave mirror, a slit blocking means and a photodetector.