Fabrication of aperiodic diffractive intraocular lenses by two-photon polymerization-based laser direct writing

Abstract

This study demonstrates the fabrication and characterization of an aperiodic diffractive intraocular lens (IOL) prototype based on the Devil’s staircase function, using two-photon polymerization (2PP). The surface profile was quantified using an optical profilometer. Through-focus modulation transfer function (TF-MTF) and the area under the modulation transfer function (MTFa) were measured on a custom optical bench. Optical simulations were performed to model the expected performance. The fabricated prototype shows that the aperiodic stepwise profile is reproduced with micron-level lateral accuracy (average base-width deviation <6.55 μm) and submicron step-height accuracy (step height error: <20 nm) across the 6-mm optical zone. The measured TF-MTF and MTFa match the predicted trifocal optical performance, exhibiting distinct focal peaks at far (0.0 D), intermediate (+1.75 D), and near (+3.6 D). These findings demonstrate the promising potential of 2PP for the rapid and precise prototyping of aperiodic diffractive IOL designs.