Analysis of a fiber-optic LP_01 ↔ LP_02 mode converter

Abstract
We investigate the intermodal coupling between LP01 and LP02 modes for a mode converter fabricated in a few-mode fiber with photorefractive gratings. Our results show that a narrow spectrum of power conversion can be obtained by reducing the index perturbation or by using a large core–cladding index difference and a small fiber core radius.