Attosecond pulses from a solid driven by a synthesized two-color field at megahertz repetition rate

TL;DR

This paper demonstrates the generation of isolated attosecond pulses at megahertz repetition rates using a synthesized two-color laser field in a solid-state material, enabling high-repetition-rate XUV sources for advanced quantum dynamics studies.

Contribution

It introduces a novel method for producing high-repetition-rate isolated attosecond pulses from a solid using a synthesized two-color field, surpassing previous kilohertz limitations.

Findings

Achieved megahertz repetition rate IAPs in solid-state high-harmonic generation.

Controlled the harmonic spectrum via two-color phase tuning.

Confirmed ~730 attoseconds pulse duration through numerical simulation.

Abstract

Probing coherent quantum dynamics in light-matter interactions at the microscopic level requires high-repetition-rate isolated attosecond pulses (IAPs) in pump-probe experiments. To date, the generation of IAPs has been mainly limited to the kilohertz regime. In this work, we experimentally achieve attosecond control of extreme-ultraviolet (XUV) high harmonics in the wide-bandgap dielectric MgO, driven by a synthesized field of two femtosecond pulses at 800nm and 2000nm with relative phase stability. The resulting quasi-continuous harmonic plateau with ~ 9 eV spectral width centered around 16.5 eV photon energy can be tuned by the two-color phase and supports the generation of an IAP (~ 730 attoseconds), confirmed by numerical simulation based on three-band semiconductor Bloch equations. Leveraging the high-repetition-rate driver laser and the moderate intensity requirements of solid-state high-harmonic generation, we achieve IAP production at an unprecedented megahertz repetition rate, paving the way for all-solid compact XUV sources for IAP generation.