# Adaptive wavefront correction of dynamic multimode beam based on modal decomposition

## TL;DR

This paper introduces a real-time adaptive wavefront correction method for dynamic multimode fiber beams using modal decomposition and holographic techniques, significantly improving beam quality.

## Contribution

It is the first to demonstrate real-time wavefront correction of dynamic multimode beams based on modal decomposition with a phase-only SLM.

## Key findings

- Achieved wavefront correction at 5Hz rate
- Improved power-in-the-bucket by 1.73 times
- Validated feasibility for large mode area fiber lasers

## Abstract

We propose and demonstrate a method for the adaptive wavefront correction of dynamic multimode fiber beams for the first time. The wavefront of incident beam is reconstructed in real-time based on the complete modal information, which obtained by using the modal decomposition of correlation filter method. For the proof of principle, both of the modal decomposition and the wavefront correction are implemented using the same computer-generated hologram, which encoded into a phase-only spatial light modulator. We demonstrate the wavefront correction of dynamic multimode beam at a rate of 5Hz and achieve a 1.73-fold improvement on the average power-in-the-bucket. The experimental results indicate the feasibility of the real-time wavefront correction for the large mode area fiber laser by adaptive optics.

---
Source: https://tomesphere.com/paper/1903.10023