Plasmonic-nanowire near-field beam analyzer

Area of Science:

• Photonics and Nanotechnology
• Plasmonics
• Optical Metrology

Background:

• Near-field analysis of micro/nano-waveguide output beams is crucial for nanophotonic device design.
• Existing beam analyzers face limitations in resolving the trade-off between measurement resolution and light collection efficiency.
• Experimental demonstration of such analyzers has been lacking.

Purpose of the Study:

• To experimentally demonstrate a novel plasmonic-nanowire near-field beam analyzer.
• To overcome the limitations of conventional beam analyzers by achieving high resolution and efficient light collection.
• To enable detailed characterization of beam properties from micro/nano-waveguides.

Main Methods:

• Utilizing a single gold nanowire (AuNW) as a probe for near-field scanning.
• Employing a reverse nanofocusing process to enhance measurement capabilities.
• Performing three-dimensional (3D) scanning from plasmonic hotspots to far-field regions.

Main Results:

• Achieved a probe resolution of 190 nm (<λ/8) with a simulated collection efficiency of ~47.4% at 1596 nm.
• Successfully characterized the 3D spatial distribution evolution of metal nanowire output beams for the first time.
• Demonstrated simultaneous characterization of complex multimodes in nanoribbons, surpassing simulation predictability.

Conclusions:

• The plasmonic-nanowire beam analyzer offers a promising solution for near-field analysis of micro/nano-waveguides.
• It provides high resolution and efficiency, enabling detailed characterization of nanophotonic structures.
• This technology holds potential for applications in nanolasers, biosensing, and fundamental understanding of nanophotonic devices.