Sub 100-fs, 5.2-$\mu$m ZGP Parametric Amplifier Driven by a ps Ho:YAG Chirped Pulse Amplifier and its application to high harmonic generation

TL;DR

This paper presents a high-repetition-rate, sub-100 femtosecond mid-infrared parametric amplifier at 5.2 μm driven by a Ho:YAG chirped pulse amplifier, enabling advanced high harmonic generation and nonlinear optical studies.

Contribution

The work introduces a novel 5.2 μm ZGP parametric amplifier with sub-100 fs pulses and a new pulse compression scheme for wavelength tunability and enhanced pulse quality.

Findings

Generated 40 μJ, 99 fs pulses at 1 kHz

Achieved high harmonic generation in ZnSe above bandgap

Demonstrated ultrafast conduction band transitions

Abstract

We report a 1 kHz repetition-rate mid-IR (MIR) optical parametric amplifier (OPA) system operating at a central wavelength of 5.2 $\mu$m with the tail-to-tail spectrum extending over 1.5 $\mu$m and delivering 40 $\mu$J pulses that are compressed to 99 fs (5.6 optical cycles). Also we develop a novel pulse compression scheme for further pulse compression and wavelength tunability. As the first application of this laser system, we generated high harmonics in bulk ZnSe above the bandgap, dense exciton generation after 10-photon absorption, high order sum- and difference-frequency generation, ultrafast transition in the conduction band, which reflects the structure of conduction bands.