Transformation of micropyramid array to microlens array with massive quantity of lenses using surface tension controlled molding

Chalcogenide glass (ChG) microlens arrays (MLAs) are highly valued in micro-optics engineering owing to their superior infrared optical properties. However, the fabrication of MLAs with massive quantity of lenses is a challenging task. In this paper, a novel surface tension controlled glass-to-glass molding method for ChG MLA fabrication is proposed. The approach utilizes the difference in transition temperature (T_g) between silicate glass and ChG, as well as the surface tension of glass in microstructures forming to transform a micropyramid array to a microlens array. A numerical model of the glass-mold interface considering the gas trapping is established to analyze and predict the variation trend of lens curvature during the molding process. The effectiveness of this method was experimentally confirmed by precision glass molding (PGM) of the ChG MLA with ten-thousand sub-lenses with a dimension of 20 μm. Finally, the exceptional consistency of the MLA is substantiated through optical performance testing based on a digital model, thus demonstrating the promising application prospects of this method.