Interferometry of dipole phase in high harmonics from solids

Journal Article · Mon Dec 17 00:00:00 EST 2018 · Nature Photonics

DOI:https://doi.org/10.1038/s41566-018-0326-x· OSTI ID:1503234

Lu, Jian ^[1]; Cunningham, Eric F. ^[1]; You, Yong Sing ^[1]; Reis, David A.  ^[1]; Ghimire, Shambhu  ^[1]

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1. SLAC National Accelerator Lab., Menlo Park, CA (United States)

Understanding the temporal profiles of high harmonics is essential for their applications in attosecond science. Microscopically, the dipole phase plays an important role in determining the high-harmonic emission phase. In gas-phase high-harmonic generation, the tunnel-ionized electron spends much of its travel time in the continuum—far from the parent ion, where it accumulates the dipole phase. Therefore, the atomic dipole phase is largely independent of the target atom. In solid-state high-harmonic generation, since the driven electron experiences a periodic potential during the entire travel time, the dipole phase may depend on the electronic structures of source materials. Here, we employ an interferometric method to characterize high harmonics from magnesium oxide and quartz crystals. We measure material-dependent intensity-induced high-harmonic phase delays that we attribute to the intensity-induced changes in the dipole phase originating from the interband polarization. The material-dependent dipole phase can provide a robust platform for high-harmonic spectroscopy of solids.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1503234
• Journal Information: Nature Photonics, Vol. 13, Issue 2; ISSN 1749-4885
• Publisher: Nature Publishing Group
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS