PRACTICAL COUPLING DEVICE BASED ON A 2-CORE OPTICAL-FIBER

A practical coupling device that relies on a dual-core fiber in a loop configuration is presented. Its coupling properties are analyzed in t erms of the optical path difference between the cores, which is contro lled by the rotation of the fiber about its axis and by a small twist applied to it along the loop. The device actually acts as an anisotrop ic coupler, and the coupled power can be perfectly controlled from 0-1 00% by proper adjustment of the loop. A simple implementation of the d evice was used in the fabrication of a compact single-fiber Michelson interferometer.