Highly Efficient Perfect Vortex Beams Generation Based on All-Dielectric Metasurface for Ultraviolet Light

Abstract

Featuring shorter wavelengths and high photon energy, ultraviolet (UV) light enables many exciting applications including photolithography, sensing, high-resolution imaging, and optical communication. The conventional methods of UV light manipulation through bulky optical components limit their integration in fast-growing on-chip systems. The advent of metasurfaces promised unprecedented control of electromagnetic waves from microwaves to visible spectrums. However, the availability of suitable and lossless dielectric material for the UV domain hindered the realization of highly efficient UV metasurfaces. Here, a bandgap-engineered silicon nitride (Si3N4) material is used as a best-suited candidate for all-dielectric highly efficient UV metasurfaces. To demonstrate the wavefront manipulation capability of the Si3N4 for the UV spectrum, we design and numerically simulate multiple all-dielectric metasurfaces for the perfect vortex beam generation by combing multiple phase profiles into a single device. For different numerical apertures (NA =0.3 and 0.7), it is concluded that the diffracted light from the metasurfaces with different topological charges results in an annular intensity profile with the same ring radius. It is believed that the presented Si3N4 materials and proposed design methodology for PV beam-generating metasurfaces will be applicable in various integrated optical and nanophotonic applications such as information processing, high-resolution spectroscopy, and on-chip optical communication.

Polarization-Insensitive, Broadband, and Tunable Terahertz Absorber Using Slotted-Square Graphene Meta-Rings

“…The EM waves can be manipulated by designing an appropriate metamaterial structure and varying the design parameters. To date, various devices in the microwave and optical regimes have been developed by exploiting the features of the metamaterials [29][30][31][32][33][34][35][36].…”

Helicity multiplexed broadband meta-holography for ultraviolet regime

“…In advanced wavefront shaping, metasurfaces with extraordinary properties overcome conventional optics [1][2][3][4][5][6][7]. The manipulation of fundamental properties of electromagnetic (EM) waves with carefully engineered subwavelength nanostructures has attracted much attention [8][9][10][11][12][13][14].…”

Application of machine-learning techniques for characteristic analysis of refractory materials

“…Metasurface based designs have shown the potential for shaping the optical wavefronts by featuring only compact footprint in contrast to the bulky geometric optics [1][2][3][4][5][6][7][8][9]. The designs become capable of providing the control by engineering the geometry and size of meta-atom [9][10][11].…”