Recovering scattered data from twisted light via 'scattering-matrix-assisted retrieval technique (SMART)'
High-capacity optical communication can be accomplished by multiplexing multiple light-carrying orbital angular momentum (OAM) channels. However, in turbulent environments, optical scattering and 'speckle patterns' occur due to ambient, atmospheric microparticles and significantly decrease the orthogonality between OAM channels, demultiplexing (extracting information) and increasing crosstalk during communication. In a recent study now published in Light: Science & Applications, Lei Gong and co-workers at the departments of optics and optical engineering, medical engineering, electrical engineering and physical sciences in China and the USA developed a 'scattering-matrix-assisted retrieval technique' (SMART) to efficiently recover scattered data from multiplexed OAM channels. In the study, they used 24 OAM channels in parallel, passing through a scattering medium to demultiplex the channels from the scattered optical fields and achieve minimal experimental crosstalk approximating -13.8 dB.