Extreme ultraviolet metalens by vacuum guiding

• 成果类型: Article
• 署名作者: Ossiander, Marcus; Meretska, Maryna Leonidivna; Hampel, Hana Kristin; Lim, Soon Wei Daniel; Knefz, Nico; Jauk, Thomas; Capasso, Federico; Schultze, Martin
• 署名单位: Harvard University; Graz University of Technology
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-12535
• DOI: 10.1126/science.adg6881
• 发表日期: 2023-04-01
• 页码: 59-63
• 关键词: high-harmonic generation; light; phase

摘要

Extreme ultraviolet (EUV) radiation is a key technology for material science, attosecond metrology, and lithography. Here, we experimentally demonstrate metasurfaces as a superior way to focus EUV light. These devices exploit the fact that holes in a silicon membrane have a considerably larger refractive index than the surrounding material and efficiently vacuum-guide light with a wavelength of similar to 50 nanometers. This allows the transmission phase at the nanoscale to be controlled by the hole diameter. We fabricated an EUV metalens with a 10-millimeter focal length that supports numerical apertures of up to 0.05 and used it to focus ultrashort EUV light bursts generated by high-harmonic generation down to a 0.7-micrometer waist. Our approach introduces the vast light-shaping possibilities provided by dielectric metasurfaces to a spectral regime that lacks materials for transmissive optics.