Surface integrity in diamond machining germanium for infrared optics

Ultra-precision manufacturing is a deterministic method of producing optical-grade components. Continuous and interruptive machine operations are the focus of this research with the goal of improving the manufacturing community’s knowledge. The original contributions of this research are: (a) a comprehensive analysis of the cutting mechanics of single-crystal germanium, specifically studying the effects of major crystal orientation in germanium and cutting speed; (b) methodology for producing flat, damage-free test samples in single-crystal germanium; and (c) machine learning model for estimating surface finish parameters Sa, Sq, and Sz for SPDT of single-crystal germanium and oxygen-free high-conductivity copper. As a final product of this research, a pair of collimating lenses were produced. AFRL funded the research for development of these lenses.