Invisibility Cloak Printed on a Photonic Chip

TL;DR

This paper demonstrates a 3D waveguide-based invisibility cloak fabricated on a photonic chip, enabling new possibilities in integrated photonics for classical and quantum applications.

Contribution

It introduces a novel method of creating an invisibility cloak using femtosecond laser direct writing on a photonic chip, which is a significant advancement over traditional approaches.

Findings

Successful fabrication of a 5000-waveguide cloak

Effective concealment of millimeter-scale objects demonstrated

Potential for on-chip quantum and classical photonic applications

Abstract

Invisibility cloak capable of hiding an object can be achieved by properly manipulating electromagnetic field. Such a remarkable ability has been shown in transformation and ray optics. Alternatively, it may be realistic to create a spatial cloak by means of confining electromagnetic field in three-dimensional arrayed waveguides and introducing appropriate collective curvature surrounding an object. We realize the artificial structure in borosilicate by femtosecond laser direct writing, where we prototype up to 5000 waveguides to conceal millimeter-scale volume. We characterize the performance of the cloak by normalized cross correlation, tomography analysis and continuous three-dimensional viewing angle scan. Our results show invisibility cloak can be achieved in waveguide optics. Furthermore, directly printed invisibility cloak on a photonic chip may enable controllable study and novel applications in classical and quantum integrated photonics, such as invisualising a coupling or swapping operation with on-chip circuits of their own.