On the ultra-precision diamond machining of chalcogenide glass

Chalcogenide glasses are important materials for components in thermal imaging systems (IR-optics). While suitable for molding, the machining characteristics of these brittle materials are largely unknown. In this paper, ultra-precision machining data for a common chalcogenide glass (As40Se60) is presented. Data acquired from orthogonal cutting experiments show a transition in cutting mechanics at an uncut chip thickness of approximately one micrometer. This data is used to identify parameters for high-speed milling, and results are used to produce a thermal imaging lens. This paper demonstrates that the milling process is suitable for prototyping and low-batch production of IR-optics in this glass.