Fractal, diffraction-encoded space-division multiplexing for FSO with misalignment-robust, roaming transceivers

For free space optical (FSO) communication, a small misalignment of the transceivers may result in link failure or severe performance degradation. It can be difficult to track the narrow optical beams over long distances. Here, we propose “diffractal space-division multiplexing” (DSDM), an FSO transmission system capable of supporting misaligned roaming transceivers. This system enables spatial multiplexing for enhanced data capacity with partial off-axis beam reception. We numerically simulate and analyze the performance of the DSDM system with a particular focus on the divergence angle, roaming area, kernel bit-error-rate (K-BER), and fractal order. Our simulation results achieve K-BERs of 10[Formula: see text] with [Formula: see text] -pixel fractal beams at link distances of 2.5 km when the receiver sizes are 30[Formula: see text] of the effective beam diameter.