Saturable Time-Varying Mirror Based on an Epsilon-Near-Zero Material

Tirole, Romain; Galiffi, Emanuele; Dranczewski, Jakub; Attavar, Taran; Tilmann, Benjamin; Wang, Yao-Ting; Huidobro, Paloma A.; Alu, Andrea; Pendry, John B.; Maier, Stefan A.; Vezzoli, Stefano und Sapienza, Riccardo (2022): Saturable Time-Varying Mirror Based on an Epsilon-Near-Zero Material. In: Physical Review Applied, Vol. 18, No. 5, 54067

Abstract

We report a switchable time-varying mirror, composed of an indium-tin-oxide-gold bilayer, displaying a tenfold modulation of reflectivity (AR approximate to 0.6), which saturates for a driving-pump intensity Ipump approximate to 100 GW/cm2. Upon interacting with the saturated time-varying mirror, the frequency content of a reflected pulse is extended up to 31 THz, well beyond the pump spectral content (2.8 THz). We interpret the spectral broadening as a progressive shortening of the mirror rise time from 110 fs to below 30 fs with increasing pump power, which is confirmed by four-wave-mixing experiments and partially captured by a linear timevarying model of the mirror. A temporal response unbounded by the pump bandwidth enables applications for spectral manipulation from time-varying systems with impact for communication networks, optical switching, and computing.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 2331-7019
• Language: English