Ultra-dispersive metasurfaces enabled by convergence-phase design using simplified nanopillar arrays.

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Metasurfaces offer unique optical field manipulation capabilities.
• Achievable dispersion in metasurfaces is limited by nanostructure complexity and phase modulation.

Purpose of the Study:

• To introduce a novel metasurface design method for achieving ultra-dispersive properties.
• To overcome the constraints of limited phase modulation in conventional metasurfaces.

Main Methods:

• Developed a metasurface design based on convergence phase.
• Utilized structurally simple nanopillars for enhanced phase modulation.
• Overlapped phase of multiple wavelengths with a central wavelength.

Main Results:

• Demonstrated an ultra-dispersive metalens with phase variations exceeding 1200π, a 30-fold enhancement.
• Fabricated metalenses with unprecedented dispersion characteristics.
• Implemented the metalens in a miniaturized chromatic confocal sensor with a 13mm range and 50nm axial resolution.

Conclusions:

• The convergence phase method enables ultra-dispersive metasurfaces with simple structures and relaxed fabrication.
• The developed metalenses show significant potential for applications like miniaturized sensors and spectral tomography.
• Established a generalizable foundation for mass-producible, ultra-dispersive metasurfaces.