Comparative performance analysis of 100% fill-factor microlens arrays fabricated by various methods

Abstract

Fill-factor of microlens arrays (MLAs) is one of the most important performance criteria of microlens arrays (MLA), especially in imaging applications. Low fill-factor lenses suffer greatly from spurious light and diffraction affects and result in low contrast in a beam steering system. Contrast ratio of low fill-factor circular shaped microlens arrays is nearly one-fourth of that of the system with high fill-factor square shaped microlens arrays. In this study performance of various types of nearly 100% fill-factor spherical MLAs in beam steering applications are compared. Design and fabrication of the MLAs are studied. A new hybrid method for design and fabrication of 100% fill-factor MLAs -by combining refractive-diffractive lenses, is suggested and tested.