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

Area of Science:

• Nanophotonics
• Optical Engineering
• Materials Science

Background:

• Ultraviolet (UV) light's short wavelengths and high photon energy are crucial for applications like photolithography and sensing.
• Conventional UV light manipulation relies on bulky optics, hindering integration into compact on-chip systems.
• Metasurfaces offer precise electromagnetic wave control, but efficient UV metasurfaces are limited by material availability.

Purpose of the Study:

• To introduce a novel, highly efficient all-dielectric metasurface for UV light manipulation.
• To demonstrate the potential of bandgap-engineered silicon nitride (Si3N4) for UV metasurface applications.
• To design and simulate metasurfaces capable of generating perfect vortex (PV) beams in the UV spectrum.

Main Methods:

• Utilized bandgap-engineered silicon nitride (Si3N4) as the dielectric material for metasurface fabrication.
• Designed and numerically simulated all-dielectric metasurfaces for UV perfect vortex beam generation.
• Investigated metasurface performance for different numerical apertures (NA=0.3 and 0.7) and topological charges.

Main Results:

• Successfully demonstrated wavefront manipulation of UV light using Si3N4 metasurfaces.
• Achieved perfect vortex beam generation with an annular intensity profile.
• Confirmed that the ring radius of the diffracted light remains consistent across different topological charges and numerical apertures.

Conclusions:

• Bandgap-engineered Si3N4 is a suitable material for highly efficient all-dielectric UV metasurfaces.
• The proposed design methodology enables effective perfect vortex beam generation for integrated photonic applications.
• These advancements hold promise for on-chip optical communication, information processing, and high-resolution spectroscopy.