Rapid manufacture of defect-free microlens arrays by precision glass molding

This paper introduces cost-effective and flexible manufacturing techniques for producing a defect-free microlens array (MLA) using different optical materials, including norland optical adhesive (NOA), polymethyl methacrylate (PMMA), and borosilicate glass P-BK7. The investigation showed that by using a proper mold, defect-free NOA, PMMA, and optical glass MLA with various geometries can be efficiently manufactured by a polymerization or a precision glass molding (PGM) process. The investigation reveals that the surface quality of NOA MLA can be significantly improved by adjusting the viscosity of the NOA monomer solution. By optimizing the viscosity, defect-free MLA of high quality can be achieved. Furthermore, the study shows that high-quality PMMA and P-BK7 MLA can be obtained by carefully controlling the molding temperature and pressure during the PGM process. The appropriate adjustment of these parameters ensures the successful fabrication of MLA with excellent surface quality and without any defects.