https://doi.org/10.1051/epjconf/202328704009
Coherent all-optical steering of upconverted light by a nonlinear metasurface
1 Politecnico di Milano, Physics Department, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
2 University of Brescia, Department of Information Engineering, Via Branze 38, 25123 Brescia, Italy
3 Université de Paris, CNRS, Laboratoire Matériaux et Phénomènes Quantiques, 75013 Paris, France
4 Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120 Palaiseau, France
* Corresponding author: agostino.difrancescantonio@polimi.it
Published online: 18 October 2023
In recent years a strong drive towards the miniaturization of nonlinear optics has been motivated by the functionalities it could empower in integrated devices. Among these, the upconversion of near-infrared photons to the visible and their manipulation is fundamental to downscale optical information. We propose a dual-beam scheme whereby a pulse at the telecom frequency ω (1550 nm wavelength) is mixed with its frequency-doubled replica at 2ω. When the two pump pulses are superimposed on a nonlinear, all-dielectric metasurface two coherent frequency-tripling pathways are excited: third-harmonic generation (THG, ω+ω+ω) and sum-frequency generation (SFG, ω+2ω). Their coherent superposition at 3ω produces interference, which we enable by filtering the k-space with the metasurface diffraction. The steering of the emission among diffraction orders, is sensitive to the relative phase between the two pumps. Therefore, by exploiting the phase as a tuning knob, the upconverted signal can be switched between diffraction orders with an efficiency >90%. The proposed approach can be envisioned as an all-optical method to reroute upconverted telecom photons.
© The Authors, published by EDP Sciences, 2023
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
