Abstract: A radiation sensor for determining the angular location of a light source and locating a direction defined by a plurality of sources fastened to a movable structure such as a helmet-mounted sight visor. The sensor comprises a housing with an optical mask which is provided with transparent zones of circular shape, with the result that the omnidirectional radiation transmitted by a point source is confined within a cone. Radiation-detecting means constituted by linear arrays of photosensitive elements are disposed in a plane parallel to the mask so that the center of the projected circle corresponding to the angular direction of the source is determined by the positions of sensitized elements of the detecting strips.

Abstract: A coupler for interconnecting transmission lines in an optical communication system. In a preferred embodiment it comprises an elongated bi-conically shaped rod of transparent material which continues into two cylindrical mixing rods. The lines are split up into two groups coupled to respective ones of the two plane endfaces of the coupler. The dimensions of each tapered central portion are determined such that the radiation pattern in the common plane of the identical minor bases is substantially hemispherical no matter what the direction of propagation of the light modes along the axis from one end to the other, given the numerical aperture of the associated transmission lines.