Details

Autor(en) / Beteiligte

• Yang, Yuanmu
• Lu, Jian
• Manjavacas, Alejandro
• Luk, Ting S.
• Liu, Hanzhe
• Kelley, Kyle
• Maria, Jon-Paul
• Runnerstrom, Evan L.
• Sinclair, Michael B.
• Ghimire, Shambhu
• Brener, Igal

Titel

High-harmonic generation from an epsilon-near-zero material

Ist Teil von

• Nature physics, 2019-10, Vol.15 (10), p.1022-1026

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• High-harmonic generation (HHG) is a signature optical phenomenon of strongly driven, nonlinear optical systems. Specifically, the understanding of the HHG process in rare gases has played a key role in the development of attosecond science 1 . Recently, HHG has also been reported in solids, providing novel opportunities such as controlling strong-field and attosecond processes in dense optical media down to the nanoscale 2 . Here, we report HHG from a low-loss, indium-doped cadmium oxide thin film by leveraging the epsilon-near-zero (ENZ) effect 3 – 8 , whereby the real part of the material’s permittivity in certain spectral ranges vanishes, as well as the associated large resonant enhancement of the driving laser field. We find that ENZ-assisted harmonics exhibit a pronounced spectral redshift as well as linewidth broadening, resulting from the photo induced electron heating and the consequent time-dependent ENZ wavelength of the material. Our results provide a new platform to study strong-field and ultrafast electron dynamics in ENZ materials, reveal new degrees of freedom for spectral and temporal control of HHG, and open up the possibilities of compact solid-state attosecond light sources. High harmonics are generated from a thin film by leveraging the epsilon-near-zero effect. These kinds of harmonic are found to exhibit a pronounced spectral redshift as well as linewidth broadening caused by the time-dependency of this effect.