Designing high-transmission and wide angle all-dielectric flat metasurfaces at telecom wavelengths

Abstract

Recent advances in holography, wireless sensing and light fidelity technologies have resulted in the need for antennas that can support highly efficient beam directivity for a broad angular range. Transmitarrays have been shown to be promising candidates for the determination of such structures. Here, we present a comprehensive methodology for the design of subwavelength all-dielectric flat metasurfaces with high transmission and deflection range. The metasurfaces are CMOS compatible and can be fabricated using conventional processing of silicon-on-insulator technology. The optimized structures exhibit up to 95% efficiency for a wide-angle deflection range from 20{\deg} to 60{\deg} in air, at operating wavelengths near 1550 nm. Furthermore, we propose the potential multi-wavelength and muti-mode excitation capabilities of the designed supercell. This is achieved by shifting the resonance of each post of the metasurface to the wavelength of interest opening up opportunities for wavelength multiplexing with a single structure. Our results facilitate the realization of broad angle flat deflectors and holographic devices but also indicate that today's bulky and expensive light fidelity optical routers could be substituted by ultra-small chips that are inexpensive to fabricate and can be commercially implemented.