Nonperturbative Generation of Harmonics by Nanometer-Scale Localized Electronic States on the Surface of Bulk Materials and Nano-Films
The generation of high-order harmonics in solid crystals has received considerable attention recently. Using a driver laser with 0.8 µm wavelength and 28 fs ultrashort pulses, we present experimental results, accompanied with theoretical considerations, suggesting that the actual sources of the harm...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-03-01
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| Series: | Optics |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2673-3269/4/1/17 |
| Summary: | The generation of high-order harmonics in solid crystals has received considerable attention recently. Using a driver laser with 0.8 µm wavelength and 28 fs ultrashort pulses, we present experimental results, accompanied with theoretical considerations, suggesting that the actual sources of the harmonics are nanometer-sized localized and transient electronic states on the surface of the materials when the laser intensity is in the non-perturbative regime. Adaptation of the bond model of the harmonic generation into the non-perturbative regime and including the quantum features of the process provide a localized excitation approach that correctly describes the measured polarization dependence of the harmonic signal, reflecting the microscopic surface structure and symmetries of the examined materials. |
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| ISSN: | 2673-3269 |