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 As2Se3.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.

Automated summary

This study fabricated convex microlens arrays on chalcogenide glass surface using femtosecond laser direct writing and precision molding. Regularly arranged damage craters were induced on silica glass surface by femtosecond laser writing. The surface of silica was then etched with hydrofluoric acid to obtain a smooth concave microlens, which was replicated on the surface of chalcogenide glass by precision molding. The resulting chalcogenide glass microlens array showed uniform structure, clear image, and good focusing effect. The method provides an efficient way to prepare large-scale microlens array masks and microlens.