Extreme ultraviolet metalens by vacuum guiding

Area of Science:

• Optics and Photonics
• Material Science
• Nanotechnology

Background:

• Extreme ultraviolet (EUV) radiation is crucial for advanced material science, attosecond metrology, and lithography.
• Existing transmissive optics for EUV light are limited by material properties.
• Metasurfaces offer a novel approach to manipulate light at the nanoscale.

Purpose of the Study:

• To experimentally demonstrate metasurfaces as a superior focusing method for EUV light.
• To leverage the unique optical properties of silicon membrane holes for light guidance.
• To introduce dielectric metasurface capabilities to the EUV spectral regime.

Main Methods:

• Fabrication of an EUV metalens using silicon membranes with precisely controlled hole diameters.
• Utilizing the difference in refractive index between silicon holes and the surrounding material for vacuum-guiding light.
• Focusing ultrashort EUV light bursts generated by high-harmonic generation.

Main Results:

• Demonstrated metasurfaces as an effective method for focusing EUV light.
• Achieved nanoscale control over light transmission phase via hole diameter.
• Fabricated a 10-mm focal length metalens with numerical apertures up to 0.05.
• Focused EUV light to a 0.7-micrometer waist.

Conclusions:

• Metasurfaces provide a powerful new tool for manipulating EUV light, overcoming limitations of traditional optics.
• This technology opens up new possibilities for light-shaping in the EUV spectrum.
• The demonstrated metalens design is suitable for applications requiring precise EUV focusing.