Solid-state high-harmonic generation goes attosecond

High-harmonic generation (HHG) produces a train of attosecond light pulses. However, many experiments in attosecond science require isolated attosecond pulses (IAPs), not just a train of pulses. IAPs generated by HHG in solids instead of gas targets are difficult to achieve and require the preparation of extremely short single-cycle infrared pulses to ensure that indeed only a single attosecond pulse is created. In our new work published in ACS Photonics, our postdoc Zhaopin Chen and M.Sc. student Mark Levit came up with an alternative route to drive HHG in a solid – synthesizing a two-color field where the two colors (800nm and 2000nm) are incommensurate to each other. We show that this scenario suppresses HHG in all but one optical cycle when using magnesium oxide (MgO) as the HHG generation medium. While our setup does not allow the direct measurement of the IAPs, a good agreement between experiment and elaborate theory calculations indicates the generation of an IAP with 700as duration at a photon energy of 17eV. In the future, we will apply these IAPs to perform exciting attosecond experiments in electron microscopy.