The Large aperture optics tag highlights lenses and mirrors with substantial diameters that are used in telescopes, high-energy laser systems, and other advanced imaging or illumination applications. Articles under this tag explore the technical challenges of fabricating, handling, and testing large optics while maintaining tight surface accuracy, homogeneity, and coating performance. Readers learn about structural and lightweighting strategies, mounting and support designs, and metrology approaches needed to ensure stable performance under gravity, temperature changes, and mechanical loads. Applications may span astronomy, space payloads, long-range surveillance, and large-scale laser or lithography tools. For engineers and program managers planning systems that rely on large apertures to gather light or deliver energy, this tag provides insights into realistic tolerances, risks, and timelines. It also demonstrates Avantier’s capabilities in delivering large, high-quality optics that meet demanding specifications for both ground-based and spaceborne platforms.