Niklas Hansson1
NIL Technology1
Metalenses have gained significant attention in various fields such as augmented reality (AR), automotive technology, and consumer electronics. Their unique properties, including high thermal stability, fewer lens components, and focal lengths that closely match design values in production. These aspects lead to simplified camera modules, and make meta lenses highly desirable for these applications.<br/> <br/>The efficiency of metalenses is crucial, as low-efficiency metalenses result in undesirable diffraction of light. To achieve high efficiency, it is important that the fabricated meta atoms, typically in the form of pillars, closely match the intended design. Even small deviations in the order of a few nanometers can lead to noticeable decreases in efficiency. Nanoimprint lithography (NIL) is a manufacturing technique employed for mass producing metalenses. We have investigated how closely the fabricated pillar diameters align with the design specifications. In the case of a focusing lens designed for 940 nm, the deviations in pillar diameters were found to be within the range of +/-10 nm for repeated fabrication on a single wafer and between consecutive manufactured wafers.<br/> <br/>The corresponding focusing efficiencies of these metalenses were measured to be between 85% and 90%. This indicates that NIL is a valid manufacturing method for producing metalenses suitable for the aforementioned applications. The high efficiency of the manufactured metalenses suggests that they effectively mitigate the issue of light diffraction into unwanted orders, making them a promising choice for AR, automotive, and consumer electronics.