Core Identification and Geometry Specifications in Multicore Optical Fibers

The common approach for specifying core geometry in multicore optical fibers (MCF) is to use the core radial position (relative to the cladding center) and the pitch between core pairs. This works well to describe the nominal MCF features but is inadequate to properly tolerance the core positions (i.e. restrict core positional errors in a manufactured MCF). A better approach is to perform an optimized alignment of the manufactured MCF against a “master” template of the MCF design core positions. This approach produces consistent, easily understood limits on core positional errors and generalizes to more complicated core patterns.