Research status and challenges in the manufacturing of IR conformal optics

The infrared conformal window is one of the most critical components in aircraft. Conformal windows with high performance bring low aberrations, high aerodynamic performance, reliability in extreme working environments, and added value for aircraft. Through the past decades, remarkable advances have been achieved in manufacturing technologies for conformal windows, where the machining accuracy approaches the nanometer level, and the surface form becomes more complex. These advances are critical to aircraft development, and these manufacturing technologies also have significant reference values for other directions of the ultra-precision machining field. In this review, the infrared materials suitable for manufacturing conformal windows are introduced and compared with insights into their performances. The remarkable advances and concrete work accomplished by researchers are reviewed.The challenges in manufacturing conformal windows that should be faced in the future are discussed.