Correction of phase and depolarization distortions in a multimode fiber at 1064 μm with stimulated-Brillouin-scattering phase conjugation

Abstract

We have used phase conjugation to compensate phase distortions and depolarization introduced in multimode fibers having 2-m lengths and 400-microm core diameters. The experiment was performed at a wavelength of 1.064 microm, and we achieved phase conjugation using Brillouin-enhanced four-wave mixing in a 0.8-mm-core hollow quartz lightguide filled with TiCl(4). The far-field conjugation fidelity was 70%, and the residual depolarization was <1%. Comparable compensation was achieved by use of either a graded-index or a step-index fiber.