PDMS-mediated precision glass molding of chalcogenide glasses aspherical microlens arrays with suppressed interfacial reaction

Aspherical microlens arrays (AMLAs) are critical components in compact infrared imaging and sensing systems. However, precision molding of AMLAs on chalcogenide glasses (ChGs) is frequently hindered by adhesion and interfacial reactions at elevated molding temperatures. In this work, a polydimethylsiloxane (PDMS) medium mold is introduced as an interfacial forming medium to enable precision glass molding (PGM) of ChGs without direct metal-glass contact, to prevent the interfacial chemical reaction. The mechanical properties of PDMS were systematically tuned by varying the base-to-crosslinker ratio and curing conditions. The curing behavior of PDMS was coupled with finite element simulations to analyze the combined effects of PDMS modulus and molding temperature on profile accuracy, providing guidance for medium mold preparation. Under optimized conditions, a 10×10 AMLAs was replicated in a single PGM cycle, achieving a peak-to-valley (PV) of 0.8 μm and a surface roughness (Ra) of 12 nm. Infrared imaging and EDS analyses confirm preserved infrared transparency and negligible change in surface composition after molding. The proposed PDMS-assisted PGM method provides an effective forming strategy for high-quality fabrication of infrared AMLAs on ChGs.