OPTICAL-FIBER ALIGNMENT USING CLEAVED-EDGE DIFFRACTED LIGHT

We describe a simple technique for aligning optical fibers prior to fu sion splicing. The technique relies on the fact that well-cleaved fibe r ends have extremely sharp edges. By making the narrow pencil of ligh t emerging from one fiber scan laterally over the entrance face of a s econd fiber, and by monitoring the light diffracted past its sharp edg es, we can locate precisely the geometric center of the output fiber. With this technique, we have aligned fiber cores with a mean lateral o ffset of 0.81 mum, the major part of this offset caused by the eccentr icity of the core relative to the cladding's circular perimeter.