Design and machining of an Archimedes spiral Fresnel lens

The production of homocentric loop Fresnel lens using diamond cutters with turning needs extremely high performance processing systems,but the production efficiencies are low.This paper gives a design method for Archimedes spiral Fresnel lens that are easy to produce.Comparison of the geometrical focusing and the energy transmissivities shows that those two kinds of Fresnel lens are almost the same.A method is then given to design the turning cutter track for large Archimedes spiral Fresnel lenses.The analysis considers the influence of the NC turning machine axes precision on the lenses optical capabilities.The primary factors affecting the lenses are the angle of cutter swing and the feed normal to the lens surface.The precision can be enhanced by a micro feeding device for the axial cutter feed.