Super-resolution laser machining

Super-resolution laser machining represents a cutting-edge advancement in precision manufacturing, striving to approach or even exceed the optical diffraction limit to produce structures with exceptionally fine feature sizes, minimal heat-affected zones, and intricate freeform patterns. The present paper provides an overview of two principal approaches developed to achieve super-resolution: one is reducing the diffraction limit through the adoption of shorter laser wavelengths or advanced focusing techniques, and the other is surpassing the diffraction limit by advanced manipulation of the laser and its interactions with materials. With a deep investigation of the principles of these super-resolution laser machining methods, the review mainly explores the recent advancements in laser characteristics manipulation, materials innovation, and the integration of adaptive optics, high-speed laser scanning equipment, and feedback systems, all of which aim at enhancing machining resolution and broadening its applicability. Focusing on research frontiers and industrial applications, we also critically discussed future directions, potential problems, and possible solutions to smaller structure manufacturing regarding the light source, optical system, laser-matter interactions, and the surface evaluation methods. It also highlights the prospects for super-resolution laser machining, emphasizing its potential to transform precision manufacturing across industries.