Mid-infrared polarization-controlled broadband achromatic metadevice

Area of Science:

• Optics and Photonics
• Materials Science
• Electromagnetics

Background:

• Metasurfaces offer compact electromagnetic wave manipulation but suffer from chromatic aberration, limiting broadband polarization control.
• Existing polarization-controlled metadevices struggle with chromatic aberration, hindering their practical application in diverse spectral ranges.

Purpose of the Study:

• To propose and demonstrate a broadband achromatic methodology for polarization-controlled multifunctional metadevices.
• To overcome the limitations of chromatic aberration in mid-wavelength infrared applications.
• To enable advanced functionalities like switchable optical vortex beams and high-performance polarization beamsplitters.

Main Methods:

• Utilized birefringent meta-atoms for broadband achromatic polarization control.
• Designed and simulated all-silicon metadevices for integration with CMOS technology.
• Demonstrated generation of polarization-controlled optical vortex beams with switchable topological charge.
• Implemented a broadband achromatic polarization beamsplitter with high polarization isolation.

Main Results:

• Achieved polarization-controlled, achromatically focused optical vortex beams with diffraction-limited spots.
• Demonstrated switchable topological charge (L∥ = 0 and L⊥ = 2) for optical vortex beams.
• Implemented a broadband achromatic polarization beamsplitter with an extinction ratio up to 21.
• The all-silicon configuration provided broad phase dispersion for high-performance metadevices.

Conclusions:

• The proposed broadband achromatic methodology significantly advances polarization-controlled metadevices by overcoming chromatic aberration.
• The developed metadevices offer multifunctional capabilities, including switchable optical vortex beams and efficient polarization splitting, suitable for practical applications.
• The all-silicon design facilitates integration with existing technologies and ensures high performance for future metadevices.