Abstract: An improved guide sleeve for receiving a pin shaped body or plug pin containing a lightwave guide to form a lightwave guide plug connection characterized by the guide sleeve having a cylindrical acceptance opening extending to at least one end for receiving the pin and terminating in an enlarged diameter cylindrical portion coaxial with the acceptance opening, and a sliding sleeve of a synthetic plastic material such as polytetrafluoroethylene being disposed in the enlarged diameter portion and having a decreasing inner diameter forming a lip adjacent one end of the sliding sleeve which one end is adjacent the acceptance opening. Thus when a pin-shaped body is inserted into the guide sleeve, the outer surface of the body will be wiped by the lip to limit or prevent the introduction of dirt or other substances into the interior of the guide sleeve.

Abstract: A method of forming an optical coupling device having plug pins received in a sleeve with one of the plug pins supporting a single waveguide and the other plug pin supporting a bundle of optical waveguides, characterized by providing the waveguides, etching the waveguides to form an end zone of a thin thickness connecting by a tapering transition zone having increasing thickness to the original cladding thickness of the optical waveguides, assembling the waveguides in an optical bundle with the end zones being arranged with the smallest spacing therebetween. Preferably, each of the plug pins has a bore with a small portion adjacent the end of the pin which corresponds to the diameter of the end zones of the bundle of waveguides.