Fabrication of terahertz meta-optics using ultrashort pulse laser processing

Meta-optics involves controlling electromagnetic wave propagation using structures at or below the wavelength scale. The terahertz frequency region is gaining interest in applications in sensing, imaging, wireless communications, and radio astronomy. Traditional lithography, used to create these microstructures, requires multiple devices and clean-room environments, which are costly and struggle with non-uniform heights. As an alternative, ultra-short pulse laser processing offers a single-equipment solution. This method, using galvanometer mirrors, achieves a beam focus diameter of 10-20 um, smaller than terahertz wavelengths (hundreds of um), enabling the fabrication of sub-wavelength structures for THz meta-optics. We have successfully used femtosecond laser processing to create terahertz meta-lenses demonstrating comparable performance to lithographic methods, as well as anti-reflection moth-eye structures. This talk will show these advancements in terahertz meta-optics using ultrashort pulsed lasers.