Atomic-Probe-Controlled Hydrogenation for Configurable Flat Optics

Area of Science:

• Nanophotonics
• Materials Science
• Surface Science

Background:

• Active nanophotonics requires materials with tunable properties and high spatial resolution.
• Existing fabrication methods for nanoscale optical elements can be complex and costly.

Purpose of the Study:

• To demonstrate a lithography-free method for fabricating flat optical diffraction gratings.
• To explore the use of probe-based nanoscale patterning for dynamic material transformation.

Main Methods:

• Utilized a platinum-coated atomic force microscopy probe for local hydrogen ion injection into NdNiO3 film.
• Investigated the changes in resistivity and lattice structure induced by hydrogen injection.
• Characterized the optical contrast and spatial resolution of the patterned areas.

Main Results:

• Achieved a seven-order-of-magnitude increase in resistivity and 12.6% lattice expansion in NdNiO3.
• Transformed areas from opaque metallic to transparent insulating states with high optical contrast.
• Demonstrated deep subwavelength spatial resolution (~100 nm) and continuous grayscale programmability.
• Successfully fabricated and optically validated microdiffraction gratings and holographic diffraction elements.

Conclusions:

• Atomic-probe-controlled hydrogen injection is an effective and energy-efficient method for prototyping programmable diffractive optical elements.
• This technique offers a powerful paradigm for next-generation flat optics fabrication.
• The demonstrated process provides high spatial fidelity and significant optical contrast for nanoscale patterning.