Nondestructive on-chip detection of optical orbital angular momentum through a single plasmonic nanohole

TL;DR

This paper introduces a tiny, nondestructive on-chip device using a plasmonic nanohole to detect optical orbital angular momentum, enhancing integrated optical communication systems.

Contribution

The work presents a novel, ultra-compact plasmonic nanohole device for efficient, nondestructive OAM detection on-chip, compatible with existing optical communication platforms.

Findings

Device size is a few hundred nanometers.

Effective in-situ OAM monitoring demonstrated.

Potential for multiplexed OAM discrimination.

Abstract

Optical orbital angular momentum (OAM) provides an additional dimension for photons to carry information in high-capacity optical communication. Although the practical needs have intrigued the generations of miniaturized devices to manipulate the OAM modes in various integrated platforms, the on-chip OAM detection is still challenging to match the newly-developed compact OAM emitter and OAM transmission fiber. Here, we demonstrate an ultra-compact device, i.e., a single plasmonic nanohole, to efficiently measure an optical beam's OAM state in a nondestructive way. The device size is reduced down to a few hundreds of nanometers, which can be easily fabricated and installed in the current OAM devices. It is a flexible and robust way for in-situ OAM monitoring and detection in optical fiber networks and long-distance optical communication systems. With proper optimization of the nanohole parameters, this approach could be further extended to discriminate the OAM information multiplexed in multiple wavelengths and polarizations.