English to German Tech/Engineering Patents In einem Patent

It's about a process of making deffractive multifocal lenses. The 'steps' in this context are 'Stufen'. 'a distinct step in optical thickness occurs at the junction between the zones.' Shoukld it be: 'eine eindeutige Stufe erfolgt' or 'eine erhebliche Stufe'?.

Thank you very much in advance!


1. A diffractive multifocal lens comprising an optical element having a first diffractive optical surface (102) having a radial surface profile (130) comprising a plurality of concentric annular zones (104) concentric with a central zone and assignable, from the outer edge of the central zone to the edge of the lens, as alternating odd and even numbered zones each having a projected surface area that is equal, wherein the optical thickness of the lens changes monotonically within each zone, a distinct step in optical thickness occurs at the junction between the zones (136, 138), the height of the steps differs between adjacent zones, and a pattern of step height differences between two or more adjacent zones repeats periodically from the center to the edge of the lens so as to tailor the proportions of the diffraction order efficiencies of at least a zeroth, positive first, and positive second, diffractive order of the radial surface profile (130) of the optical element.