Wafer-Scale Functional Metasurfaces for Mid-Infrared Photonics and Biosensing

Area of Science:

• Nanophotonics and Metasurface Technology
• Mid-Infrared Optics and Photonics
• Materials Science for Optical Applications

Background:

• Metasurfaces offer nanoscale light manipulation for advanced optical functionalities.
• Practical application of metasurfaces is hindered by low-cost, high-throughput fabrication challenges.
• Fabricating mid-infrared metasurfaces is particularly difficult due to material limitations.

Purpose of the Study:

• To develop a versatile, scalable, and cost-effective nanofabrication process for mid-infrared metasurfaces.
• To overcome material constraints for mid-infrared metasurface fabrication.
• To demonstrate the functionality and efficiency of fabricated mid-infrared metasurfaces.

Main Methods:

• Utilized transparent free-standing metal-oxide membranes for metasurface realization.
• Implemented wafer-scale and complementary metal-oxide-semiconductor (CMOS)-compatible manufacturing techniques.
• Fabricated dielectric and plasmonic metasurfaces for the mid-infrared spectrum.

Main Results:

• Demonstrated highly uniform and functional mid-infrared metasurfaces.
• Achieved high-Q structures for spectral selectivity, large-area metalenses with diffraction-limited focusing, and efficient birefringent metasurfaces for polarization control.
• Integrated aluminum plasmonic metasurfaces with microfluidics for label-free mid-infrared biosensing of proteins and lipid vesicles.

Conclusions:

• The developed nanofabrication approach overcomes limitations in mid-infrared metasurface production.
• The method's versatility and mass-production compatibility significantly advance commercial applications.
• Enables practical use of infrared metasurfaces in thermal imaging, spectroscopy, and biosensing.