Design And Fabrication of High Numerical Aperture And Low Aberration Bi-Convex Micro Lens Array

TL;DR

This paper presents the design and fabrication of a bi-convex micro lens array with high numerical aperture and low aberration using PDMS, thermal reflow, and copper sputtering, suitable for optical applications.

Contribution

It introduces a novel bi-convex semispherical micro lens array design with high NA and low aberration, fabricated through a simple process.

Findings

Achieved NA of 0.379 with low aberration

Successfully fabricated the micro lens array using thermal reflow and sputtering

Demonstrated the feasibility of the fabrication process for optical applications

Abstract

Micro lens array is crucial in various kinds of optical and electronic applications. A micro lens array with high numerical aperture (NA) and low aberration is in particular needed. This research is aimed to design and fabricate such a micro lens array with simple structure while keeps the same NA of a same-diameter hemisphere lens. A bi-convex semispherical micro lens array, with corresponding NA 0.379, by PDMS is first designed and analyzed. Experiments are further conducted to fabricate the designed micro lens array by the thermal reflow process. The formed profile is then sputtered with copper to serve as the mold. The front and the rear micro lens array are fabricated by plating PDMS to the mold and then assembled to form the designed micro lens array.