2D uniform high-contrast metastructure for single mode VCSEL

We introduce a uniform two-dimensional high-contrast metastructure (2D-HCM) mirror that converts an oxide-aperture 850 nm VCSEL to single-mode operation without extra epitaxy or tight lithography. Its period exceeds half a wavelength and the duty cycle is ~50 %, allowing full-wafer nano-imprint fabrication. The 2D HCM can suppress higher-order modes, giving side-mode suppression above 20 dB while maintaining milliwatt output and >20 GHz modulation bandwidth. This scalable, low-cost solution enables dense arrays of single-mode VCSELs for short-reach optical interconnects, chip-to-chip links, and high-resolution 3D sensing.