Samsung Advanced Institute of Technology

Printable metalenses composed of a silicon nanocomposite are developed to overcome the limitations to manufacturing of conventional metalenses. The nanocomposite is synthesized by dispersing silicon nanoparticles in a thermally-printable resin to achieve not only high refractive index for high-efficiency metalenses, but also printing compatibility for inexpensive manufacturing of metalenses. The synthesized nanocomposite exhibits high refractive index > 2.2 in the near-infrared regime, and only 10％ uniform volume shrinkage after thermal annealing, so the nanocomposite is appropriate for elaborate nanofabrication compared with commercial high-index printable materials. A 4-mm-diameter metalens operating at the wavelength of 940 nm is fabricated using the nanocomposite and one-step printing without any secondary operations. The fabricated metalens verifies a high focusing efficiency of 47％, which can be further increased by optimizing the composition of the nanocomposite. The printing mold is reusable, so the large-scale metalenses can be printed rapidly and repeatedly. A compact near-infrared camera combined with the nanocomposite metalens is also demonstrated, and a captured image of veins underneath a human dermis confirms the applicability of the nanocomposite metalens for biomedical imaging.