Abstract
We hereby propose and theoretically investigate a new scheme for simultaneous generation and manipulation of terahertz (THz) waves through difference frequency generation facilitated by a metasurface-assisted nonlinear leaky waveguide antenna. The proposed structure integrates a nonlinear optical waveguide, composed of multiple AlxGa1−xAs layers, with a THz leaky waveguide, wherein a bianisotropic metasurface realizes the radiating aperture. By explicitly utilizing the electric, magnetic, and magnetoelectric coupling responses of the metasurface, we demonstrate that the generated THz wave can be induced as a tightly confined, phase-matched guided mode for efficient generation of the THz wave. Additionally, this approach allows the THz wave to be transformed into a directive beam, radiating at a user-defined leakage rate and direction. Our numerical analyses suggest that THz beams ranging from 2.85 THz to 3.05 THz can be steered from 4◦ to 40◦, utilizing the inherent beam-steering capabilities of the leaky-waveguide antenna. Within this THz frequency spectrum, the phase matching condition is achieved by adjusting the optical wavelengths between 1.6µm and 1.52µm. In particular, the nonlinear conversion efficiency is 2.9 × 10−5 [1/W] at 3 THz.
Original language | English (US) |
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Pages (from-to) | 5837-5850 |
Number of pages | 14 |
Journal | Optics Express |
Volume | 32 |
Issue number | 4 |
DOIs | |
State | Published - Feb 12 2024 |
Bibliographical note
Publisher Copyright:© 2024 Optica Publishing Group (formerly OSA). All rights reserved.
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- Journal Article