IR Diamond Turned Lens
Many commercial LWIR lenses (e.g. IR diamond-turned lens) are currently two-element solutions. Diamond turning is a main component of the infrared optics manufacturing requirements, although AR coatings are also a critical part of the process. Coating IR materials can be quite challenging and expensive because of the relatively thick layers that are required. The long wavelengths typically help the assembly requirements by making them less sensitive than comparable visible wavelength assemblies in precision optical products.