Ultrafast all-optical modulation of wide-bandwidth pulses enabled by silicon-metasurfaces
Journal article, 2026
Semiconductor metasurfaces have emerged as an effective platform for all-optical modulation thanks to their resonant light confinement and the enhancement of ultrafast optical effects like the Kerr effect and free-carrier generation. However, their narrow resonance features also restrict the available bandwidth for efficient modulation. Here, we demonstrate that a kink-like transmission spectral profile of a silicon metasurface could enable high-contrast modulation of wide-bandwidth pulses. We studied the all-optical ultrafast transmission modulation of the silicon metasurface induced by free-carrier excitation in a pump-probe configuration at different polarizations. We achieved ultrafast modulation of 28% (10%) with a speed of 25 ps and a bandwidth of up to 14 nm (49 nm) for y-and x-polarizations, respectively. Our results open up new opportunities for high-contrast, all-optical modulation of short pulses, with applications in optical communications and computing.
pump-probe spectroscopy
metasurfaces
nanophotonics
ultrafast tuning
Author
Kaloyan Georgiev
Sofia University
Khosro Zangeneh Kamali
Chalmers, Physics, Nano and Biophysics
Anton A. Trifonov
Sofia University
Giulia Crotti
Polytechnic University of Milan
Lyuben Petrov
Sofia University
Stefan Georgiev
Sofia University
Hristo Iliev
Sofia University
Lei Xu
Nottingham Trent University
Unai Arregui Leon
Polytechnic University of Milan
Mohsen Rahmani
Nottingham Trent University
Giuseppe Della Valle
Polytechnic University of Milan
Ivan Buchvarov
Bulgarian Academy of Sciences
Sofia University
Dragomir Neshev
Australian National University
Sofia University
OPTO-ELECTRONIC ADVANCES
2096-4579 (ISSN) 2097-3993 (eISSN)
Vol. In PressSubject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Telecommunications
DOI
10.29026/oea.2026.260007