Abstract: An optical element for incorporation into optical transmission means and comprising an optical fiber provided with a coating with a substantially circular cross section applied essentially coaxially closely around the fiber, to which coating is imparted such an adhesion to the optical fiber that a contraction tendency in the coating brought about in connection with the application of the coating affects the fiber with such an axial compressive force in its whole length that the force causes a real shortening of the fiber and a corresponding increase of the elongation at break of the fiber. The fiber can be provided with an intermediate protective layer, and an intermediate adhesive layer can be used. Optical transmission means comprising one or more optical elements in a sheath are described.

Abstract: A process and apparatus for continuously transforming a flat metal strip into an elongated pipe, in which the strip is fed through a forming tool along a curved forming path wherein the longitudinal edge portions are progressively turned up into cross-sectionally arcuate portions leaving between a substantially cross-sectionally rectilinear section, the width of which progressively decreases during travel of the strip through the forming tool. The curved forming path in the tool is such that it has a radius of curvature R(z) in its longitudinal direction, the arcuate portions each having a radius r.sub.o and the decreasing width of said rectilinear section being 2x(z) (wherein z is the distance of travel through the tool). The radius of curvature R(z) is controlled in sole dependence on r.sub.o and the differential quotient x'(z).

Abstract: An optical element for use in optical transmission comprising one or more optical fibers provided with an essentially tight-fitting coating and a strength member provided with an essentially tight-fitting coating of the same material, each of said coatings having an essentially circular cross-section, wherein the coating or coatings on the optical fibers are firmly connected with the coating on the strength member by connection means of the same material, and whose thickness is substantially smaller than the diameter of the coatings and where further the fiber or fibers are given a curve or wave shaped course. The connection means can be a continuous or locally broken fin and the coating can be applied commonly or separately around the fibers. Optical transmission means comprising such optical elements are described.

Abstract: A process for preparing an optical element comprising an optical fiber located in a tubular jacket in a curve shape with a radius of curvature sufficiently big to avoid a substantial increase of the loss at light transmission in which process by establishing elastic tensions varying over the cross-sectional area of the element, the element is given such a permanent preshape that when placed in the tubular jacket it has a marked tendency to assume by itself the desired curve shape. The fiber itself can be preshaped or it can be provided with an eccentric coating or a segmented multicomponent coating having different contraction tendencies. An optical element so produced and an optical transmission means comprising such an element is also described.