Abstract: A fiber optic coupler is formed by providing a glass tube having a longitudinal aperture extending therethrough. Protective coating is removed from a region of a first optical fiber intermediate the ends thereof. Protective coating is removed from an end region of at least one other optical fiber. The coated portion of the first fiber is threaded through the tube until the uncoated region thereof is near the tube end. The size of the aperture is insufficient for simultaneously receiving the coated portions of the first and second fibers in side-by-side relationship at the coated portion of both. The uncoated region of the second fiber is placed adjacent that of the first fiber, and both uncoated regions are simultaneously fed into the tube aperture.

Abstract: A fiber optic coupler is formed by providing a glass tube having a longitudinal extending aperture. Protective coating is removed from a region of a first optical fiber intermediate the end. Protective coating is removed from an end region of at least one other optical fiber. The coated portion of the first fiber is threaded through the tube until the uncoated region is near the tube end. The uncoated region of the second fiber is placed adjacent that of the first fiber, and both uncoated regions are simultaneously fed into the tube aperture. The threading operation is continued until the uncoated regions extend through the midregion of the tube, the midregion is heated to collapse it about the fibers, and the central portion of the midregion is drawn to reduce the diameter along a predetermined length.