Silicon nitride metalens for optical imaging

We report an ultrathin silicon nitride metalens for optical imaging. The meta-surface of silicon nitride provides the full phase delay in a broad range of visible wavelengths. The metalens was fabricated with E-beam... [ view full abstract ]

We report an ultrathin silicon nitride metalens for optical imaging. The meta-surface of silicon nitride provides the full phase delay in a broad range of visible wavelengths. The metalens was fabricated with E-beam lithography, lifting-off and RIE processes. The beam spots focused through the metalens were measured at 405, 533, and 633 nm in wavelength, respectively. The captured images of the USAF chart exhibit that the metalens clearly distinguishes line pairs with 10 μm apart. The silicon nitride metalens highly compatible to further MEMS fabrication can be utilized in optical MEMS devices for miniaturized optical imaging and illumination applications.