Couplings designed and configured to optically couple light conductors in light-conducting cables to tools that require light at working regions of the tools. Examples of such tools include endoscopes and microscopes. Each coupling couples one or more pairs of light conductors, for example, optical fibers, with each other by locating the ends of each pair in confronting relation and by holding the light conductors so that their optical axes are substantially coaxial with one another. In this manner, light is efficiently transmitted through the confronting ends to minimize losses across the interface. Each coupling can include one or more pairs of mechanically interengaging alignment structures for ensuring that the light conductors are aligned properly.
