Abstract: A variable attenuation optical fiber coupling arrangement is for coupling two fibers mounted in connectors in end to end relationship. The end faces of each of the fibers is at an angle to its respective fiber axis. A coupling member is adapted to receive the connectors. Each connector has a locating key and the coupling member has keyways to receive each connector key. The key on at least one of the connectors and its corresponding keyway are rotatably positioned relative to the fiber end face so as to introduce a measured amount of mis-alignment of the end face relative to the other fiber end faces.