Metalens manufacturing complexities and costs

Abstract

Background: Metalenses are flat devices that focus and manipulate optical waves. Unlike reflective and refractive optics, metalenses rely on phase shifts introduced by subwavelength metastructures. Aim: Demonstrate the cost and performance impact of using manufactured metaatoms from two lithography processes to design and manufacture metalenses. Approach: Design two types of metalenses, the first type (ideal) uses an ideal design made up of square metaatoms. This lens design is then simulated using both 193 nm and 248 nm lithography processes. The second type (manufactureaware) uses a design that is built around metaatom profiles produced by the corresponding lithography process (193 nm and 248 nm respectively). By comparing the performance of these two approaches (ideal and manufacture-aware) we demonstrate the process performance impact can be reduced. Results: Comparing 193 nm and 248 nm processes show a up to a 27% difference in monochromatic metalens performance for a design derived from ideal metaatoms. However, by simulating manufactured metaatoms and using them in the design stage, manufactured metalens performance returns to within 7% of ideal. Conclusions: When designing with manufactured metaatoms rather than ideal metaatoms, metalens performance is similar between both 193 nm and 248 nm processes and manufacture-aware design makes either process viable for visible-light metalens manufacturing.