3.5 kW coherently combined ultrafast fiber laser

TL;DR

This paper presents a 3.5 kW ultrafast fiber laser achieved through coherent beam combination of four ytterbium-doped fibers, offering high power, excellent beam quality, and low noise in a turn-key system.

Contribution

It demonstrates a high-power ultrafast laser with coherent beam combination, including automated alignment, achieving record power and beam quality in a turnkey setup.

Findings

Delivered 3.5 kW average power

Pulse duration of 430 fs at 80 MHz

Excellent beam quality (M2<1.24x1.10)

Abstract

An ultrafast laser based on coherent beam combination of four ytterbium-doped step-index fiber amplifiers is presented. The system delivers an average power of 3.5 kW and a pulse duration of 430 fs at 80 MHz repetition rate. The beam quality is excellent (M2<1.24x1.10) and the relative intensity noise is as low as 1% in the frequency span from 1 Hz to 1 MHz. The system is turn-key operable as it features an automated spatial and temporal alignment of the interferometric amplification channels.