Twisted non-diffracting beams through all dielectric meta-axicons

• DOI: 10.1039/c9nr04888j
• Publication Date: 2019-09-30T19:21:32Z
• Authors: Nasir Mahmood; Heonyeong Jeong; Inki Kim; Muhammad Qasim Me...; Muhammad Zubair; Ali Akbar; Murtaza Saleem; Muhammad Sabieh A...; Farooq Ahmad Tahir; Junsuk Rho
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

We demonstrate transmission-based all-dielectric, highly efficient (≈73.4%) and polarization-insensitive meta-axicons (for the visible wavelength of 633 nm) to generate zero higher order Bessel beams without using additional components. The beams, owing their diverse applications non-diffractive properties, attract great interest from scientific community. It is shown that propagation length can be increased through a lower numerical aperture (∼2600 λ for NA = 0.1) whereas full width at half maximum (< 0.5 λ) obtained ≥ 0.7). Our dielectric material, hydrogenated amorphous silicon (a-Si:H), provides significant efficiency advantage over plasmonic other high-index all-dielectric (e.g., TiO2 GaN) metasurfaces in terms cost, ease fabrication, CMOS compatibility. finite difference time domain (FDTD) technique based numerically simulated experimental results show excellent agreement. Due technological importance recommended material provide an compact platform realizing various advanced like optical manipulation, alignment, laser imaging, machining.