Anti-Hermitian photodetector facilitating efficient subwavelength photon sorting.

Area of Science:

• Optics and Photonics
• Nanotechnology
• Materials Science

Background:

• Spectral beam splitting is crucial for various optical applications like imaging and energy harvesting.
• Subwavelength spectral splitting using optical antennas is a recent advancement but faces limitations in spectral control and device integration.
• Existing methods struggle with efficient spectral control and integration into optoelectronic devices.

Purpose of the Study:

• To overcome limitations in spectral control and device integration for subwavelength spectral splitting.
• To demonstrate a chip-scale device capable of sorting photons by wavelength and generating photocurrent.
• To introduce a novel approach for enhanced optical device design.

Main Methods:

• Fabrication of a single-layer metafilm with resonant photodetector elements.
• Utilizing anti-Hermitian coupling between photodetector elements for spectral sorting.
• Demonstrating lateral sorting of photons below the free-space diffraction limit.

Main Results:

• Achieved near-unity photon-sorting efficiencies and near-unity absorption.
• Demonstrated a narrow spectral response of approximately 30 nm for different wavelength channels.
• Successfully extracted useful photocurrent from spectrally sorted photons.
• Showcased a chip-scale demonstration of the metafilm's capabilities.

Conclusions:

• The developed metafilm overcomes previous limitations in spectral control and device integration.
• This technology enables efficient, chip-scale spectral sorting and photocurrent generation.
• Opens new design paradigms for image sensors and energy harvesting systems.