Manufacturing and testing of complex freeform optics at Safran Reosc: goals and achievements

Freeform optics enable complex optical designs unattainable with traditional spherical or aspherical surfaces. They allow enhanced system performance, compactness, and improved aberration correction, which are critical for advanced imaging, sensing, and space applications. However, the manufacturing and testing of freeform optics present significant technical challenges, particularly in achieving nanometric surface accuracies and precise metrology for highly non-axisymmetric shapes. This paper presents the criteria established at Safran Reosc to define and assess complex freeforms, highlights recent achievements on missions such as Microcarb, Sentinel 2 and ELT, and discusses the manufacturing and metrology strategies developed to meet stringent specifications for future generations of freeform optics.