275 W average output power from a femtosecond thin disk oscillator operated in a vacuum environment

TLDR

The study introduces an ultrafast thin‑disk laser achieving 275 W average output power, surpassing all previous mode‑locked oscillators. The laser uses a Yb:YAG thin disk with 583‑fs pulses at 16.3 MHz, a 16.9 μJ pulse energy and 25.6 MW peak power, with a high‑damage‑threshold SESAM to initiate soliton mode‑locking and a vacuum cavity to suppress atmospheric nonlinearity. Soliton mode‑locking was achieved with modest self‑phase modulation and negative group‑delay dispersion, demonstrating a path toward kilowatt‑level femtosecond oscillators.

Abstract

We present an ultrafast thin disk laser that generates an average output power of 275 W, which is higher than any other modelocked laser oscillator. It is based on the gain material Yb:YAG and operates at a pulse duration of 583 fs and a repetition rate of 16.3 MHz resulting in a pulse energy of 16.9 μJ and a peak power of 25.6 MW. A SESAM designed for high damage threshold initiated and stabilized soliton modelocking. We reduced the nonlinearity of the atmosphere inside the cavity by several orders of magnitude by operating the oscillator in a vacuum environment. Thus soliton modelocking was achieved at moderate amounts of self-phase modulation and negative group delay dispersion. Our approach opens a new avenue for power scaling femtosecond oscillators to the kW level.