Method and apparatus for an optical four-gate coupler

Abstract

Method and apparatus for an optical four-gate coupler wherein the junction between two large fiber optical waveguides of the same diameter are connected to a fiber optical waveguide having a smaller diameter and wherein a guide part is formed with a groove for engaging the small fiber optical waveguide and the distance from the center line of said groove to the edge of the guide is equal to the diameter of the larger waveguides so that the guide part and a detent can hold the two large waveguides and the smaller waveguide in aligned contacting positions and a cover plate fits over at least the two large waveguides. Such structure is then cut transverse to the center axis of the three waveguides and the ends are polished and then coupled together so as to provide an optical four-gate coupler. The modification comprises forming a groove having a width equal to the diameter of the larger fiber optical waveguide fibers and a depth which is equal to two times the diameter of a thick fiber plus one time the diameter of the smaller fiber and wherein a number of smaller fibers are placed in the bottom of the groove and the two larger fibers are placed into the groove on top of the smaller fibers and are pressed with a cover member against the smaller fibers so that at least one of the smaller fibers is in good aligned contact with one of the larger fibers.