Quasi-periodic micro-lens array via laser-assisted wet etching

Abstract

A close-packed micro-lens array (MLA) is widely used not only in novel optical systems but also in various engineering fields, such as semiconductors and display devices. In this paper, we present a simple and efficient method for fabricating MLAs on a glass substrate via laser ablation with a single femtosecond laser pulse and chemical wet etching in a hydrofluoric acid solution. The shapes of concave micro-lenses were optimized for laser pulse energy and etching time, and & SIM;70 000 micro-lenses with 15 mu m diameter were formed. The shape of the micro-lens varies significantly with respect to the etching time in accordance with an initial ablated area (or laser energy), which is a key feature in fabricating micro-lenses of several tens of mu m. Using the glass MLA as a mold, a polydimethylsiloxane convex-plano lens array was replicated, and the performance of the optical imaging and beam integrator was then examined. (C) 2022 Author(s).