Presentation
18 June 2024 Hard antireflective coatings in the visible band
Yusi Wang, Weidong Shen, Chenying Yang, Tingting Zheng
Author Affiliations +
Abstract
Antireflection coatings with sapphire-like hardness are highly desired in advanced engineering applications. Currently, classic (LH)^n structures based on Si3N4/SiO2 stacks are widely used to obtain high optical transparency and surface hardness in industry. However, it still suffers from low durability and multiple failures after wear and scratch tests. Herein, we selected Ta2O5/Si3N4 nanolaminates to fabricate toughened AR coatings with similar refractive indices, overcoming the brittleness of thick nitride films. Furthermore, we proposed another graded AR coating, using a“Step up-step down" method to combine the hardness gradient structure with optical design. The toughened AR coating exhibited a low reflectance of 0.8% (420-780 nm) and a remarkable hardness of 22.8 GPa, meanwhile demonstrating the ability to withstand abrasion from steel wool up to 3,000 times. The graded AR coating achieves high transparency (Tave>98.8%, 420-720 nm), high surface hardness (H>23 GPa), and low residual stress (~680 MPa). Notably, no additional damage was observed during 6 months after the scratch test, such as cracking, peeling, and delamination.
Conference Presentation
© (2024) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yusi Wang, Weidong Shen, Chenying Yang, and Tingting Zheng "Hard antireflective coatings in the visible band", Proc. SPIE PC13020, Advances in Optical Thin Films VIII, PC130200Q (18 June 2024); https://doi.org/10.1117/12.3016606
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KEYWORDS
Antireflective coatings

Biomedical optics

Transparency

Nanolithography

Optical coatings

Optical design

Optical fabrication

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