High-Quality and High-Efficiency Fabrication of Microlens Array by Rotary Profile Cutting Method

To enhance the fabrication consistency and surface quality of microlens array (MLA) molds, this study presents a high-quality and high-efficiency rotary profile-cutting (RPC) method conducted on a four-axis ultraprecision machining platform. A geometric model is established to define the relationship between tool parameters and microlens structural features, and the toolpath is optimized by refining control points to enhance machining accuracy. In addition, a novel tool-setting error characterization approach is developed, enabling submicron-level positioning of the diamond tool, with errors in the X and Y directions controlled within 1 μm. Experimental validation demonstrates the successful fabrication of a 6 × 6 square-array MLA mold with a curvature radius of 507 μm using the proposed RPC method. Subsequent replication of MLA through precision glass molding (PGM) yielded structures with a peak-to-valley (PV) value below 354 nm and surface roughness (Ra) below 11 nm. Optical performance tests confirm the high consistency and accuracy of the fabricated MLA, highlighting the potential of the proposed RPC technique for advanced optical component manufacturing.