Compact laser system delivering 2-\mu m few-cycle pulses for strong-field experiments at 200 kHz repetition rate

TL;DR

This paper introduces a compact, high-repetition-rate laser system generating sub-20 fs pulses at 2 μm with high stability, enabling advanced strong-field experiments such as high-order harmonic generation.

Contribution

The paper presents a novel, stable, and compact laser system capable of delivering high-energy, few-cycle pulses at 200 kHz, suitable for strong-field physics applications.

Findings

Pulse duration less than 20 fs at 2 μm

Pulse energy stability of 0.19% over 2000 pulses

System operates at 200 kHz repetition rate

Abstract

Laser pulses in the near-infrared spectral range with a high repetition rate and high pulse energy offer the possibility to perform strong-field experiments such as high-order harmonic generation in gases or strong-field photoemission from the surfaces of nanostructures. Here, we present a compact laser system that delivers ultrashort pulses with a duration of less than 20 fs in the spectral range around 2 $\mu$m and with a pulse energy of up to 30 $\mu$J. The 200-kHz system consists of a commercial turnkey pump laser followed by three home-built frequency conversion/parametric amplification stages. We find an excellent pulse energy stability of 0.19 % measured over 2000 consecutive pulses averaged over 5 minutes for the output pulses of the conceptually simple and passively carrier-envelope phase stable system. An outlook on strong-field experiments performed with the laser system is given.