Beamforming optical antenna arrays for nano-bio sensing and actuation applications

摘要

Light is found at the basis of bidirectional interfaces between digital systems and biological systems, including those in nano-bio-sensing and nano-bio-actuation applications. Despite the potentially very small size of optical transceivers and antennas, enabled by the very small wavelength of optical electromagnetic radiation, currently, existing systems commonly rely on macro-sized and intrusive equipment, including table-top microscopes and spectroscopy systems, and fiber optical technology as opposed to wireless setups. These place several bottlenecks between the possibilities and the capabilities of these emerging fields. In this paper, a unified theory is developed to design optical nano-antenna arrays, which are able to manipulate light similarly to how antenna arrays manipulate RF radiation. First, the applications of optical nano-antenna arrays in transmission, reception and reflection are described. Then, the fundamental factors affecting the design of individual optical antennas are described and modeled. The mutual coupling between optical nano-antenna is studied to guide the development of compact antenna arrays. Different beamforming strategies are proposed, and their performance is numerically investigated by means of finite element methods. (C) 2021 Elsevier B.V. All rights reserved.