Phase-controlled pattern-tunable optical traveling wave antenna array

An optical phased array is designed based on equally spaced identical Au waveguides serving as optical traveling wave antennas (OTWAs). Phased surface plasmon polaritons are fed through the Au waveguides and partly radiate out at the terminals. The simulation results indicate that the pattern maximum of a 7-element OTWA array can be dynamically steered over a range of up to 60.6 degrees by changing the excitation phase differences between the elements, and the main lobe is narrowed compared to the single-element case. A theoretical analysis about the tunable pattern by the pattern multiplication principle is carried out, which is basically consistent with the simulations. Such an OTWA array should have potential applications in nano-optics due to its ability to steer the pattern without mechanical motion. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.