Fabrication of chalcogenide microlens arrays by femtosecond laser writing and precision molding.

In this study, convex microlens arrays (MLAs) on chalcogenide glass (ChG) surface were fabricated through femtosecond laser direct writing and precision molding. Femtosecond laser writing was first employed to induce regularly arranged damage craters on the surface of silica glass. Then, the surface of silica was etched with hydrofluoric acid to obtain a smooth concave MLA. Finally, the concave microlens of silica was replicated on the surface of ChG by precision molding to obtain ChG MLA. The resulting ChG MLA had a uniform structure, clear image, and good focusing effect. By optimising the parameters of laser direct writing and chemical etching, we produced 1600 rectangular and hexagonal microlenses from As 2 Se 3.The optical performances of MLAs were demonstrated by their excellent imaging and focusing capabilities. The method applied provides an efficient way to prepare large-scale MLA masks and MLAs. [ABSTRACT FROM AUTHOR]