Emission Directionality of 3D-Printed Photonic Nanowires.

Photonic devices can be advanced by increasing the density of the integrated optical components. As the integration density increases, the potential for signal interference between adjacent components, optical crosstalk, becomes a concern. To address the crosstalk issue, it is crucial to identify the emission directionality of the integrated optical components. In this study, we investigate the emission directionality of 3D printed light-emitting nano/microwires. We experimentally and numerically showed that when the diameter is reduced below the single-mode cutoff, the emission becomes noticeably directional. In addition, our demonstrations on pairs of closely positioned wires show that optical crosstalk can be effectively avoided by reducing the diameter to the nanoscale to exploit the strong directionality of its emission. We expect that our study can be applied to various fundamental research and applications in the fields of photonics, optical communication, sensing, and imaging, where the directionality of the emissions is crucial.