Design and fabrication of low-cost thermal imaging optics using precision chalcogenide glass molding

Aspheric and diffractive surfaces in infrared materials are traditionally fabricated by single point diamond turning, which is a high-cost, low-throughput process, not suitable for low-cost, high-volume applications. Precision molding of chalcogenide glasses is a novel process we developed to allow the efficient fabrication of quality infrared optics in large volumes. In this paper we present the advantages and particularities of designing thermal imaging lenses for high-volume applications using precision molded chalcogenide glasses. As an example, we present a compact 19 mm F/1.1 infrared lens design for a 320 × 240 uncooled detector array operating from 8 to 14 microns. The excellent image quality and transmission of tested prototypes prove that precision molding of chalcogenide glasses is an ideal optical fabrication technology for the high-volume production of infrared optics.