Anti-Reflective Meta-Surfaces (ARMS) for High-Power Lasers

Eyal Feigenbaum | 18-ERD-005

Project Overview

We studied a method for modifying a thin layer on a substrate surface to alter its refractive index (i.e., a meta-surface , or MS). The MS fabrication process is based on substrate directional etching through a metal nano-particle mask, which is formed using dewetting of a thin metal layer. The local MS index depends on the mask nanoparticle (NP) fill factor (FF). We also showed that for sub-melting temperature (solid-state dewetting) the mask FF depends on the locally induced temperature. For applications requiring uniform index (e.g., anti-reflective layer) we used furnace-based dewetting, whereas for patterning the index for thin optics application we used computer-controlled laser beam raster. During the etching step, both the MS features' height and side-wall angle could be altered between cones and cylinders nano-features. We developed a predictive model for fabrication of anti-reflective meta-surfaces (ARMS) per a given reflection specification, and we validated it experimentally. We demonstrated broadband ARMS at the ultraviolet and at the near infrared. Laser-damage testing has shown relatively high threshold, as well as high mechanical robustness. This method is relatively simple and scalable, and the resulting MS is all-glass-made and robust; therefore, it offers the potential to advance high-power, high-energy laser optics technology.

Mission Impact

The ARMS technology developed during this is project is strongly aligned with Lawrence Livermore National Laboratory's core competency in lasers and optical science and technology, as well as advanced materials and manufacturing, specifically for material design and manufacturing and for scaling-up laser-optics designs. The technology enables new laser system designs and enhances the energetics, performance, and stability of high-energy/high-average power/short-pulse lasers. ARMS technology could advance critical components to laser system, such as anti-reflective coatings and diagnostics beam splitters, by its added flexibility of optical design—bandwidth, angular acceptance, reflectivity—and its laser and mechanical robustness.


Publications, Presentations, and Patents

Feigenbaum, E. 2019a. "Enhanced Tunability of Gold Nanoparticle Size, Spacing, and Shape for Large-Scale Plasmonic Arrays." ACS Appl. Nano Mater.2, 4395-4401. LLNL-JRNL-771023

——— 2019b. "Optical Modeling of Random Anti-Reflective Meta-Surfaces for Laser Systems Applications." Applied Optics58, 7558-7565. LLNL-JRNL-778537

——— 2019c. "Scalable Light-Printing of Substrate-Engraved Free-Form Metasurfaces. ACS Appl. Mater. Inter.11, 22684-22691. LLNL-JRNL-763964 2019. "Fabricating large aperture and durable meta-optics for powerful lasers." SPIE Photonics West, San Francisco, CA, February 2019. LLNL-CONF-781438

——— 2020a. "A new approach to meter-scale and durable all-dielectric meta-optics: gains and challenges." META2020 (postponed). LLNL-CONF-805046

——— 2020b. "A simpler approach to meter-scale and durable all-dielectric meta-optics." SPIE Optics and Photonics (online). LLNL-CONF-804399

——— 2020c. "Coupling an engraved meta-surface with buried etalon layers as a scalable approach for durable and large aperture meta-optics." Appl. Opt., 59. 8136. LLNL-JRNL-808360

——— 2020d. "Scalable and durable glass-engraved meta-surfaces for high power laser ultra-thin optics." SPIE Laser Damage (online). LLNL-ABS-807165

——— 2020e. “Nanostructured Layer For Graded Index Freeform Optics.” U.S. Patent 10,612,145.

Feigenbaum, E., et al. 2018. "Robust and scalable meta-surfaces for powerful lasers applications." MRS Spring Meeting, Phoenix, AZ, April 2018. LLNL-CONF-760584

——— 2019a. "Durable meta-optics for powerful lasers applications." Fall MRS Meeting, Boston, MA, December 2019. LLNL-CONF-777421

——— 2019b. "Enhanced control of Au nanoparticles features during large aperture generation." SPIE optics + photonics, San Diego, CA, August 2019. LLNL-CONF-766239

——— 2019c. "Scalable and robust meta-optics for laser applications." SPIE optics + photonics, San Diego, CA, August 2019. LLNL-CONF-766238

——— 2019d. “Angled directional etching through a mask to form a bi-refringent meta-surface.” U.S. Patent Application No. 16/518,500.

——— 2020. “Repeated metal deposition-dewetting steps to form a nano-particle etching mask producing thicker layer of engraved metasurface.” U.S. Patent Application No. 16/875,337.

Ray, N. 2020. "Substrate-engraved antireflective nanostructured surfaces for high-power laser applications." Optica. 7. 518. LLNL-JRNL-805293

Ray, N., et al. 2019. "Quest for High Damage Performance: Metasurfaces for High Power Laser Applications.” SPIE Laser-induced Damage in Optical Materials, Broomfield, CO, September 2019. LLNL-ABS-772939

Yoo, J. and E. Feigenbaum, 2019. “System and method for ablation assisted nano structure formation for graded index surfaces for optics.” U.S. Patent Application No. 16/016,105, Published Patent Application US2019/039,1298 A1.

Yoo, J., et al. 2018. "Direct Printing of Gold Nano-Particles by Laser Induced Dewetting." CLEO Proceedings. LLNL-PROC-763560

——— 2019. "Direct Printing of Gold Nano-Particles by Solid-State Dewetting." SPIE Photonics West Proceedings. 2019. LLNL-PROC-781505