Micro-optics are essential in modern consumer devices and imaging systems, including mobile phones and cameras, where multiple micro-optical components enable high-resolution performance [1]. Despite advances in microfabrication, processing fused silica remains challenging due to its hardness and brittleness [2]. Current laser-based fabrication approaches rely on multi-step processes, including rough shaping by femtosecond laser or etching followed by CO₂ laser polishing [3]. While effective, these methods can introduce shape inaccuracies, involve chemical processing, and induce thermal subsurface damage, limiting overall surface quality and process efficiency.

Femtosecond laser direct figuring and finishing enable non-contact, single-step fabrication with high geometric accuracy and without tool marks [4–7]. In this work, direct femtosecond laser fabrication of a convex microlens array on fused silica is demonstrated, producing optical-quality surfaces without post-polishing. White-light interferometry shows a surface roughness below 1.5 nm per microlens, and 96% lens-to-lens uniformity is achieved across the array. The fabrication methodology, process control, and scalability are presented.

[1] Res. Tech. 84(11), 2784–2806 (2021).

[2] C. Lin et al., J. Non-Cryst. Solids 629, 122860 (2024).

[3] P. Wu et al., Adv. Photon. Res. 4(4), 2200227 (2023).

[4] G. Chen and J. Qiao, Opt. Lett. 47(15), 3860 (2022).

[5] C. Otieno and J. Qiao, Opt. Mater. Express 15(7), 1510 (2025).

[6] G. Chen et al., Opt. Express 33, 23252–23259 (2025).

[7] C. Otieno and J. Qiao, Proc. SPIE 13728, 137280I (2025).