A system for use in TFL lithotripsy procedures uses a silica trunk fiber semi-permanently mounted in an endoscope and includes a detachable and replaceable wave guide treatment tip, including hollow wave guides and fiber tips. The system provides for ready removal and replacement of wave guides damaged during lithotripsy. The trunk fiber in the endoscope tube is of diameter 200 m, suitable for use in the lower pole of the kidney, and should be useful over-and-over with only the detachable wave guide removed and replaced, whether during a single procedure or for multiple procedures on different patients in which the endoscope tube and trunk fiber are sterilized between patients. Multiple connector assemblies are provided for optical coupling contact between the detachable wave guide and trunk fiber and include a gap for dissipation of heat between the trunk fiber and the wave guide when in optically coupling contact.