Abstract: The invention provides a method and apparatus for aligning an optical fiber and a semiconductor laser. The positions of the laser and of the fiber are located with respect to a fixed reference system, which is an optical detector which identifies the transverse light emission of the laser. With the laser position, the fiber is advanced so that it "flies over" the laser: the fiber then modulates the light received by the detector of the reference system. The fiber is moved back by a known amount and is moved by scanning in the plane transversal to the emissive axis of the laser, until a second optical detector, placed at the other end of the fiber, receives a maximum of light transmitted by the fiber.

Abstract: Arc lamp illuminator which can be used in an optical device for the transfer of patterns, incorporating a mixed fibre bundle which intercepts in an image plane of the source part of the emitted radiation. The exit cross-section of the bundle is adapted to the degree of coherence of the desired illumination measured on the pupil of the optical transfer device. At the entrance, the fibres of the bundle are assembled into two separate bundles, whose ends are aligned with the maximum intensity zone formed in the image plane of the source.

Abstract: An illuminator for supplying a divergent illuminating beam from an area of predetermined energy distribution and dimensions comprising a coherent source whose image is formed in a plane by imaging means incorporating electrically controlled optical scanning means making it possible to displace the image in the said area in accordance with a predetermined law.

Abstract: An optical system for aligning two patterns particularly by photo-repetition in which a first pattern formed by two optical networks, disposed along two coordinate axes is illuminated by the image of a second pattern comprising two optical networks, forming a reference produced from the orders of diffraction. In a variation, the optical networks are formed from a series of parallel strokes whose thickness and spatial distribution in a first direction parallel to one of the coordinate axes are determined by a pseudo-random code; the strokes of the optical networks of the first pattern being furthermore interrupted periodically in a second direction orthogonal to the first direction so as to form an optical network with a constant pitch in this direction. The optical alignment system comprises means for detecting the intensity of a predetermined part of the orders of diffraction in the second direction.

Abstract: Illuminating device comprising a laser source providing a coherent beam with gaussian distribution of intensity and means for separating the initial beam into four parts along two orthogonal directions, means for recombining the four parts resulting in their partial superimposition in a predetermined plane and means for averaging the interferences produced in the plane by the four parts.

Abstract: The method consists in recording at least one reference mark on each of the patterns corresponding to the various levels of the circuit at a fixed point, in recording the reference mark of the first pattern in the semiconductor plate at the same time as the first pattern and then, after each positioning of the thin plate after the chemical treatments, in centering, by displacing the thin plate relative to the pattern, the images in the plane of the following pattern of at least two reference marks situated in the different zones with the complementary reference mark carried by the following pattern to be projected, the thin plate then being aligned with the following pattern to be projected.

Abstract: The invention relates to optical systems intended for the transfer of patterns onto a photosensitive surface. The system according to the invention comprises a source of coherent radiation which is intended to illuminate the photosensitive surface for a predetermined duration and which is associated with transmission means introducing a wavefront modulation of the radiation intended to average during the exposure time, the interference fringes produced by the coherence of the radiation.