Abstract: An improved optical printing head is described including a linear array of light sources, and a lens array comprised of graded index optical fibers arranged in a hexagonal close-packed array, there being at least three rows of individual fiber lenses. The linear array of light sources is aligned with, and parallel to, lines of symmetry of the graded index lens array, where the lines of symmetry are defined as lines along said graded index lens array which will transmit a line of light incident thereon with a minimum deviation in the intensity of light transmitted through the lens array. A photosensitive surface on a rotating drum is provided onto which light images from the optical printhead are incident. The print head can be used in optical printing machines.

Abstract: A coupler for coupling optical energy transmitted by optical fibers to a thin-film optical waveguide and a method of manufacture. In the method an optical fiber is sandwiched between a pair of substrates and the substrates and fiber are bonded together with a suitable material. The bonded product is then cut to provide a surface including a cross section of the fiber. After polishing this surface a thin-film optical waveguide is then provided on the surface including the fiber end. The cutting angle is chosen such that, in the assembled coupler, the exit angle with respect to the waveguide surface is greater than the critical angle of the guide material. In this fashion the optical energy coupled from fiber to guide is trapped in the guide.The apparatus includes an optical fiber in a substrate with a cross section of the fiber in the surface of the substrate with a thin-film optical waveguide overlying the substrate surface.