Demonstration of Broadband Inter-Modal Four-Wave Mixing in Graded-Index Few-Mode Fibers

Abstract

We experimentally demonstrate broadband four-wave mixing (FWM) between two spatial modes of a 5-km-long few-mode fiber. We show that, in contrast to FWM in single-mode fibers, inter-modal FWM (IM-FWM) can be better phase matched for waves well separated in frequency (a few THz) than when they are closely spaced (tens of GHz).