Editorial: Advanced fabrication techniques for high-precision optical components

depends on mastering process physics across scales from interface chemistry and residual stress to tool kinematics and closed-loop control. This Research Topic highlights advanced fabrication routes that not only improve individual process parameters but also deepen our understanding of the mechanisms governing accuracy, surface integrity, manufacturability and functional performance.A recurring message across the Topic is that precision fabrication is no longer defined only by the final shape of a component. It is equally determined by what happens at interfaces, during energy transfer and throughout process integration. This broader perspective is especially clear in the contributions addressing molding and polishing. Zhao and Zhang provide a timely overview of mold-glass adhesion in precision glass molding, identifying wettability, work of adhesion, coating stability and thermomechanical evolution as key factors that control both product quality and mold durability. Their analysis is important because it reframes demolding not as a secondary step but as a central scientific and engineering problem in scalable optics manufacturing. In a complementary direction, Jian et al. examine femtosecond laser polishing of silicon nitride and position ultrafast processing as a green non-contact route for difficult-to-machine optical ceramics. By linking material removal physics to process windows and industrial outlook, this contribution extends the Topic from component fabrication toward future-ready surface engineering.At the level of glass structuring, Henkel et al. address one of the persistent challenges in optical manufacturing: the generation of high-aspect-ratio internal features in fused silica. Their comparison of deep drilling and helical drilling, with and without ultrasonic tool oscillation, shows that the effectiveness of assistance depends strongly on the kinematic strategy. Most notably, ultrasonic excitation substantially improves dimensional fidelity in helical drilling, while deep drilling remains advantageous for bore-wall quality and accuracy under the selected conditions. Beyond the immediate drilling results, this study is significant because it points toward more flexible manufacturing of complex internal optical geometries including structures relevant to fiber preforms and precision glass devices.The Topic also demonstrates that fabrication advances are equally critical in active and freeform optics. Man and Bifano present an electromagnetic deformable mirror that combines silicon micromachining with a stress-resilient assembly concept. By moving the adhesive interface to the distal ends of slender integral posts, they reduce assembly-induced face-sheet distortion while retaining a compliant structure capable of large actuation. The resulting prototype achieves bidirectional actuation with total stroke exceeding 20 μm and millisecondscale dynamic response, illustrating how fabrication design and functional optical performance must be considered together. In another contribution, Santiago-Alvarado et al. develop a practical route for manufacturing a toroidal aluminum mold for polymeric lenses successively using five-axis CNC milling, polishing, null-screen testing and coordinate measurement. Their work is valuable not only for the mold itself but also for the lower cost and more accessible pathway it demonstrates for freeform optics manufacturing and verification.In summary, the contributions in this Research Topic point to several important themes in advanced optical fabrication. First, interface-related phenomena play an increasingly important role in shaping process outcomes, from mold-glass adhesion in precision glass molding to adhesive stress in adaptive optics and laser-material interaction in ceramic finishing. Second, the Topic underscores the value of hybrid process strategies, in which assistance methods, assembly concepts, polishing steps, and metrology are combined to extend fabrication capability. Third, the studies show that metrology and process design are becoming more closely linked, supporting more robust and application-oriented manufacturing routes for highprecision optical components.Overall, this collection bridges fundamental process mechanisms with practical manufacturing challenges across passive and active optics, brittle glasses and advanced ceramics, and both high-end and cost-effective production routes. Rather than treating fabrication as a sequence of isolated steps, the articles highlight the importance of integrating materials understanding, process control, surface engineering, and metrology. This broader perspective is likely to remain important for the development of next-generation high-precision optical components with improved accuracy, surface integrity, and manufacturability.Keywords: high-precision optical components, advanced fabrication, ultraprecision machining, freeform optics, surface finishing