This invention relates to an advance in the delivery of laser beams to internal surgical sites using optical fibers with a novel distal tip design made using a fusion assembly procedure suitable for directing laser beams out of the side of an optical fiber. This side-fire fiber delivery tip assembly is fabricated by fusing a transparent tube onto the distal ends of a laser beam delivery fiber and an associated coaxial stub fiber that have beveled and parallel end faces that meet inside of the transparent tube. The result is a rugged fiber delivery tip assembly that is almost entirely solid, except for a very narrow gap between the beveled end surfaces of the two fibers. A loose fitting transparent capsule is placed over this fiber tip to contain a transparent perfluorocarbon lubricating oil or a perfluorocarbon heat-transfer agent that serves as a cooling agent for the fiber tip assembly.
