FEASIBILITY STUDY ON PRECISION COMPRESSION MOLDING OF CHALCOGENIDE GLASS MICRO-OPTICAL ELEMENTS

摘要

Chalcogenide glasses are emerging as low-cost alternatives for infrared applications. These materials have promising characteristics that can improve both manufacturing processes and device performance. In this paper, we aim to develop a complete manufacturing process based on precision compression molding of chalcogenide glass. The entire process chain includes mold fabrication, compression molding and profile measurement. A set of mold inserts was designed and fabricated by high-speed single-point diamond milling. The structure of the lower mold insert was semi-closed, which helps both molding and de-molding. Molding experiment was conducted on a commercial precision molding machine with optimized processing parameters. After the molded element was released, the profile of the replicated infrared element was measured using interferometer, which closely matched the dimensions of the curvature of lenslet on the mold. An optical setup was used to validate the optical performance of the molded microlenses. This study demonstrated the feasibility of the proposed manufacturing method, which will greatly improve fabrication efficiency of infrared elements and allow low-cost high-precision infrared micro-optics to be manufactured in high volume.