Full-Space and Arbitrary Orbital Angular Momentum Multiplexed Beam Manipulation with a Titanium Dioxide Metadevice

Area of Science:

• Photonics
• Metamaterials
• Optics

Background:

• Titanium oxide (TiO2) metasurfaces offer advanced control over visible light.
• Orbital angular momentum (OAM) beams provide additional degrees of freedom for light-matter interactions.
• Manipulating multiple OAM channels in a single device is crucial for integrated photonics.

Purpose of the Study:

• To experimentally demonstrate an all-dielectric metasurface for generating, spatially multiplexing, and focusing OAM light.
• To achieve broadband manipulation of OAM beams in both angular and distance domains.
• To develop ultracompact on-chip metadevice for versatile photonic applications.

Main Methods:

• Fabrication of an all-dielectric metasurface using spatially rotated TiO2 nanofins.
• Experimental demonstration of OAM beam generation and manipulation.
• Characterization of broadband performance for spatial multiplexing and focusing.

Main Results:

• The metasurface successfully generated, multiplexed, and focused OAM light.
• The device reconstructed four distinct OAM beams into four different directions.
• Broadband focusing into four different planes was achieved simultaneously.
• The device demonstrated spatial multiplexing of OAM light in angular and distance domains.

Conclusions:

• The demonstrated TiO2 metasurface enables versatile control and multiplexing of OAM light.
• This ultracompact on-chip metadevice holds potential for advanced photonic applications.
• The technology paves the way for miniaturized optical systems with integrated functionalities.