Open AccessOpto-thermally controlled beam steering in nonlinear all-dielectric metastructures
Author(s) -
Davide Rocco,
Marco Gandolfi,
Andrea Tognazzi,
Olesiya Pashina,
George Zograf,
Kristina Frizyuk,
Carlo Gigli,
Giuseppe Leo,
Sergey Makarov,
Mihail Petrov,
Costantino De Angelis
Publication year - 2021
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.440564
Subject(s) - optics , beam steering , materials science , second harmonic generation , signal beam , beam (structure) , signal (programming language) , modulation (music) , optoelectronics , wavelength , laser , harmonic , dielectric , nonlinear optics , physics , quantum mechanics , computer science , acoustics , programming language
Reconfigurable metasurfaces have recently gained a lot of attention in applications such as adaptive meta-lenses, hyperspectral imaging and optical modulation. This kind of metastructure can be obtained by an external control signal, enabling us to dynamically manipulate the electromagnetic radiation. Here, we theoretically propose an AlGaAs device to control the second harmonic generation (SHG) emission at nanoscale upon optimized optical heating. The asymmetric shape of the used meta-atom is selected to guarantee a predominant second harmonic (SH) emission towards the normal direction. The proposed structure is concurrently excited by a pump beam at a fundamental wavelength of 1540 nm and by a continuous wave (CW) control signal above the semiconductor band gap. The optical tuning is achieved by a selective optimization of meta-atoms SH phase, which is modulated by the control signal intensity. We numerically demonstrate that the heating induced in the meta-atoms by the CW pump can be used to dynamically tune the device properties. In particular, we theoretically demonstrate a SH beam steering of 8° with respect to the vertical axis for an optimized device with average temperature increase even below 90° C.