Wavefront shaping for optimized many-mode Kerr beam self-cleaning in graded-index multimode fiber

TL;DR

This paper demonstrates how wavefront shaping can control Kerr beam self-cleaning in multimode fibers, enabling targeted mode excitation and improved beam quality through adaptive input phase profiling.

Contribution

It introduces an experimental method using adaptive wavefront shaping to selectively excite low-order modes in multimode fibers for Kerr self-cleaning.

Findings

Successful control of Kerr self-cleaning in multiple LP modes

Power threshold increases with mode order

Adaptive phase profiling enables mode-specific beam shaping

Abstract

We report experimental results, showing that the Kerr beam self-cleaning of many low-order modes in a graded-index multimode fiber can be controlled thanks to optimized wavefront shaping of the coherent excitation beam. Adaptive profiling of the transverse input phase was utilized for channeling the launched power towards a specific low-order fiber mode, by exploiting nonlinear coupling among all guided modes. Experiments were carried out with 7 ps pulses at 1064 nm injected in a five meters long multimode fiber operating in the normal dispersion regime. Optimized Kerr beam self-cleaning of five different LP modes is reported, with a power threshold that increases with the mode order.