Method of reproducibly making fiber optic coupler

Abstract

A fiber optic coupler is formed by providing a glass tube having a longitudinal aperture extending therethrough. Glass optical fibers, each having a core, cladding and coatng are disposed within the longitudinal aperture, the fibers extending beyond each end thereof. The coating is removed from that portion of the fibers in the midregion of the tube but remains on that portion of the fibers extending into the ends of the apertures. The aperture is formed by a plurality of flattened walls, the dimensions and orientations of which are such that the cross-section of the aperture in the central region of the tube is symmetrical with respect to a plane passing through the longitudinal axis of the tube. At any cross-section of the aperture that is adjacent the coated regions of the fibers, each fiber coating contacts two walls of the aperture. The fibers are held taut to effect a tension therein, and the midregion of the tube is heated, collapsed about the fibers, and drawn to reduce the diameter thereof over a predetermined length.

Dependencies are inferred from the claim text.