Multiple Multicolored 3D Polarization Knots Arranged along Light Propagation

Area of Science:

• Optics and Photonics
• Metamaterials
• Vector Beam Generation

Background:

• Polarization and color are crucial for optical phenomena and information encoding.
• Controlling light fields in three dimensions (3D) with polarization and color is increasingly important for compact optical systems.
• Simultaneous longitudinal control of 3D optical structures with color and polarization has not been previously reported.

Purpose of the Study:

• To develop lightweight optical elements for simultaneous control of polarization and color in 3D space.
• To engineer longitudinally variable 3D optical structures for enhanced information encoding capacity.
• To propose a metasurface approach for generating multiple 3D polarization knots with engineered polarization profiles.

Main Methods:

• Utilized a metasurface approach to generate multiple 3D polarization knots along the light propagation direction.
• Engineered each knot to feature two colors and a specific 3D polarization profile.
• Controlled the observation region along the light propagation to obtain different multicolored 3D polarization knots.

Main Results:

• Successfully generated multiple 3D polarization knots, each with two colors and engineered 3D polarization.
• Demonstrated the ability to obtain different multicolored 3D polarization knots by adjusting the observation region.
• Achieved simultaneous control of polarization, color, and longitudinal properties in a 3D environment.

Conclusions:

• The proposed metasurface approach offers extra degrees of freedom for engineering complex vector beams.
• The developed metadevices provide unique properties with design flexibility and compactness.
• This paves the way for small-volume polarization systems applicable to complex structured beams and encryption.