Photonics-based Bessel beam launcher with an air-filled core and cylindrical Bragg gratings in the cladding
Year: 2024
Type: article
Abstract: In this study, we develop a photonics-based Bessel launcher characterized by a hollow-core cylindrical waveguide surrounded by Bragg gratings composed of concentric silicon rings, each 375 nm thick. The meta-surface is constructed on a 5 𝜇m high silicon cylindrical substrate. This configuration effectively generates a Bessel beam at the commonly used telecom infrared optical wavelength of 1.55 𝜇m. We explore three variations of this optical antenna, featuring 6, 16, and 32 ring arrays, respectively. The performance of the optical antenna configuration is assessed through simulated far-field polar plots and z-directed intensity distributions up to a non-diffracting range (NDR) of 1 mm using CST Microwave Studio and Lumerical FDTD Interconnect. These simulations reveal that the optical antenna gain of the launcher in the far field varies from 20 dBi to 26 dBi as the number of concentric rings increases from 6 to 32. We report the 𝑆11 reflection coefficient of -33 dB and radiation efficiency of 0.01 dB. To independently verify the angular spectrum of the antenna, we employ Dyadic Green’s functions, orthogonal vector wave functions, and Bloch’s theorem in MATLAB, demonstrating exceptional coupling of the Gaussian beam into the photonic device with a radiation efficiency of 99%.
DOI: 10.1364/josab.544483
Institution: New York University Abu Dhabi
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funder: New York University Abu Dhabi
OpenAlex ID: W4405703618