Abstract: Method for optically measuring submicron dimensions of an object or covering between two objects, and device implementing such method, wherein a light beam (23) is emitted by means of an arc lamp (22) into a system (21) with an optical monofibre (8) having a diameter larger than 500 .mu.m and a length longer than 3 m, the beam (23) is focussed to the object to be measured through the lens (32) of a microscope, the reflected beam passing through the microscope lens is separated from the incident beam in order to direct it towards the sensors of the matrix cameras (41, 42) of the charge coupling type and the spatial signals thus obtained are processed in order to reconstitute the contours of the object or to measure the covering between the two objects.

Abstract: The width of a line projecting out of or recessed on a medium such as an integrated circuit is measured. A device for that purpose includes a confocal optical assembly having a monomode light source delivering a beam having a flat wave front. An optical deflector scans the surface of the medium transversely to the line width of the beam. A separator separates the light beam directed towards the medium carrying the line from the beam reflected by the medium. A detector includes a blade placed at a position conjugate with the focal point of the optical assembly and orthogonal to the line whose width is to be measured and a differential sensor placed at a position conjugate with the pupil of the optical assembly and delivering a signal responsive to the difference of lighting on each side of the blade for comparison with a threshold.

Abstract: A laser apparatus comprising a resonant cavity, which comprises an assembly of two different reflectors and inside which is disposed an active medium capable of generating a radiation under the action of excitation means connected to said active medium. In addition, the apparatus comprises at least one supplementary resonant cavity of structure, similar to the preceding one, comprising an assembly of two different reflectors, and means for controlling the displacement of said resonant cavities making it possible to bring one or the other of said cavities coaxially into alingment with said active medium.

Abstract: This invention relates to a system for strictly positioning along an axis an object such as a wafer of semi-conducting material during a process of constructing integrated circuits, wherein it comprises:means for controlling the drive means for causing the carriage to make a displacement of acquisition of which the amplitude is at least equal to the step of the second optical grating;a generator generating, during said displacement of acquisition, a periodic reference signal, of period equal to the step of said second grating;multiplication means for forming the product of said period reference signal and of the signal actually delivered by said photoelectric sensor;means for summing the signal formed by the succession of said products;calculating means for determining the possible offset existing between said optical gratings; andmeans controlling the drive means to bring said optical gratings into strict alignment.

Abstract: A linear guiding system incorporating rolling members, having a central element and a peripheral element connected to each other by at least one pair of rolling member assemblies associated with blocks fixed on the peripheral element by means of screws, and disposed opposite one another on either side of the central element. There is a device for adjusting the pressure exerted by the rolling members on the central element when the fixing screws are loosened. The pressure adjusting device is outside of the guiding system and is adapted to be temporarily fast with the blocks, and comprises apparatus for measuring the pressure exerted by the rolling members on the central element.