Experimental performance of silica GIO fibers with a highly elliptic core

A silica graded-index oval-core fiber with a highly elliptic core has been successfully fabricated for the first time. The core radii along the major and minor axes are 50 and 12 μm, respectively, giving a core aspect ratio of 4.2. Experiments show that a circular modal field of a standard single-mode fiber operating at a wavelength of 980 mm could be transformed into an elliptic field having an aspect ratio of up to 8.0. A numerical investigation was also performed and the results agreed closely with those obtained by the experiments.