Optical fiber taps have been increasingly used in optical communication networks such as local area networks to interconnect various computer terminals, printers and/or instruments. As is well known to those skilled in the art, an asymmetric optical fiber tap allows an "ongoing" optical signal to propagate therethrough in a "downhill" direction, from an "ingoing" fiber to an "outgoing" fiber, while tapping a small portion of the optical signal for receipt at a terminal or other device connected to the tap. It also allows for an efficient launch of an optical signal into the ingoing fiber in the "uphill" direction. Optical communications systems require taps that are simple in design, easy to connect, cause minimal loss of optical energy to the ongoing signal propagating through the tap, and do not subject the fibers to disruptive forces.
U.S. Pat. No. 4,802,723 to Miller discloses an optical fiber tap formed by bending an optical fiber and substantially surrounding a portion of the fiber with a tube which couples the tapped optical energy to a detector. However, the disclosed optical fiber taps require bending of the fiber which may ultimately damage the fiber. Therefore, they can be difficult to manufacture and tend not to be very durable. Further, they do not provide for the efficient launching of optical energy in the uphill direction into the ingoing optical fiber.