Fabrication of chalcogenide glass lens module for thermal security camera

Abstract

Although the development of small formats (640x480 pixel arrays) and amorphous silicon microbolometers has greatly decreased detector cost, another important component of a thermal camera, optics, still prohibit a breakthrough for highvolume commercial systems. Aspheric lenses used in the thermal imaging are typically made using the costly single point diamond turning(SPDT) process of expensive single crystal materials (Ge and ZnS, etc). As a potential solution to reduce cost, compression molding method using chalcogenide glass has been attracted to fabricate IR optic. The present paper reports fabrication of a molded chalcogenide glass lens module for thermal security camera. In addition, the molded chalcogenide glass lens was evaluated through form error, roughness and decentration for each surface of the molded lens. From evaluation results, we verified that the molded lens is capable of adopting to thermal imaging applications.