Diamond milling or turning for the fabrication of micro lens arrays: Comparing different diamond machining technologies

Diamond-micro milling and ultra-precision free-form turning technologies for fabricating micro lens arrays (MLA) with a large number of lenslets are explained in detail and compared. Besides the programming of the toolpath, correction loops and cutting parameters are presented. Both technologies are compared regarding achievable form deviation, roughness and economic factors like machining time. The paper offers a guideline for ultra-precision machining of micro lens array master molds on planar substrates and curved surfaces.