Cost-Effective and Environmentally Friendly Mass Manufacturing of Optical Metasurfaces Towards Practical Applications and Commercialization

Optical metasurfaces consisting of two-dimensional nanostructures have rapidly developed over the past two decades thanks to their potential for use as optical components, such as metalenses or metaholograms, with ultra-compact form factors. Despite these rapid developments, major challenges for the commercialization of metasurfaces still remain: namely their mass production and use in real-life devices. A lot of effort has been made to overcome the limitations of electron beam lithography which is commonly used to fabricate metasurfaces. However, a breakthrough in mass production is still required to bring the cost of metasurfaces down into the price range of conventional optics. This review covers deep-ultraviolet lithography, nanoimprint lithography, and self-assembly-based fabrication processes that have the potential for the mass production of both cost-effective and environmentally friendly metasurfaces. We then discuss metalenses and future displays/sensors that are expected to take advantage of these mass-produced metasurfaces. The potential applications of mass-produced optical metasurfaces will open a new realm for their practical applications and commercialization.