Nonlinear manifestations of photon acceleration in time-dependent metasurfaces: tunable broadband harmonics generation

• DOI: 10.48550/arxiv.1710.06966
• Publication Date: 2017-01-01
• Authors: Maxim R. Shcherbakov; Kevin Werner; Zhiyuan Fan; Noah Talisa; Enam Chowdhury; Gennady Shvets
• Keywords: Photon Upconversion; Harmonic

Time-dependent nonlinear media, such as rapidly generated plasmas produced via laser ionization of gases, can increase the energy individual photons and generate tunable high-order harmonic pulses. This phenomenon, known photon acceleration, has traditionally required extreme-intensity pulses macroscopic propagation lengths. Here, we report on a novel material$-$an ultrathin semiconductor metasurface$-$that exhibits efficient acceleration at low intensities. We observe signature manifestation acceleration: third-harmonic generation near-infrared with frequencies reaching up to $\approx3.1\omega$. A simple time-dependent coupled-mode theory, found be in good agreement experimental results, is utilized predict new path towards radiation sources that combine resonant upconversion broadband operation.