Robust optical topologies through real world channels

Abstract

Optical topologies have received growing attention due to their potential robustness through a variety of channels. However, there is yet to be any substantial test of these topologies in real-world scenarios. Optical Skyrmions are a popular choice as they are relatively easy to generate, scale and measure. Here, we provide the first demonstration of the resilience of these states to both scattering and turbulence media. We first simulate these media with spatial light modulators, allowing use to generate a variety of topologies and finely tune the properties of the media. With robustness confirmed in a controlled setting, we then probe inorganic and biological samples as well as a 270m real-world free space turbulent link. In all cases we can show that the topological wrapping number remains remarkably close to the initial value. We observe minimal crosstalk between the transmitted topological numbers in each medium of interest and demonstrate secure information transfer with the use of a topological alphabet, with fidelities above 97% in almost all cases. This robustness is achieved without any need to probe the properties of the channel and is free of any pre- or post-correction. This work paves the way for the real-world application of optical topologies for secure and efficient high dimensional classical and quantum communication and imaging.