Large-area microlens arrays fabricated on flexible polycarbonate sheets via single-step laser interference ablation

A single-step method for the fabrication of large-area microlens arrays on flexible polycarbonate sheets is described. On areas of approximately 1 cm2, 17 million to 120 million microlenses ranging in size from sub-micrometer to several micrometers are fabricated via deep-UV pulsed laser interference ablation. The uniformity and surface quality of fabricated microlens arrays are examined and confirmed through atomic force microscopy and scanning electron microscopy. Optical imaging performance of the microlenses, and their use in massively parallel, pulsed laser nanofabrication on silicon is demonstrated. The microlens arrays can be fabricated in a matter of seconds, suggesting the potential for fast and low-cost production on flexible plastic substrates.