Optical configurations for applying antireflective nanotexture on spherical lenses by ultrashort laser structuring

• Published in: Optical review (Tokyo, Japan) Vol. 31; no. 4; pp. 459 - 473
• Main Authors: Csőke, Lóránt Tibor, Skoulas, Evangelos, Kollár, Zsolt
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01.08.2024
• Subjects: Atomic; International Symposium on Imaging; Japan; Lasers; Microwaves; Molecular; Optical and Plasma Physics; Optical Devices; Optical Memory (ISOM’ 23); Optics; Photonics; Physics; Physics and Astronomy; Quantum Optics; RF and Optical Engineering; Sensing; Special Section: Regular Paper; Takamatsu; Femtosecond laser nanostructuring; Antireflective nanotexture; Inverse-hypercentric objective; Ultrashort laser structuring of spherical surfaces
• ISSN: 1340-6000; 1349-9432
• DOI: 10.1007/s10043-024-00894-4

This paper focuses on minimizing the optical reflection on spherical fused silica lenses using femtosecond (fs) laser nanostructuring. A unique type of nanopillar formation has been observed on SiO 2 surfaces possessing antireflective properties when irradiated with a specific number of overlapping pulses, polarization, and fluence levels. Maintaining precise control over these sensitive technological parameters such as defocus and incident angle during the processing of geometrically complex shapes presents a significant challenge. This study proposes a theoretical optical arrangement to address this limitation by the design of a custom scanner system optimized for curved surfaces. The paper details the optimization process of such a bent image space (inverse-hypercentric) optical system using Zemax OpticStudio. Although the practical realization of the arrangement has not been performed, simulations are conducted to prove the functionality of the concept. Furthermore, we propose a practical method for segmented structuring of spherical surfaces based on consecutive repositioning and irradiation using an industrial robotic arm. By constructing the optical model, the necessary resolution of the segmentation has been calculated for a typical F-Theta scanner system and experimental verification has been performed.