Space-division multiplexing (SDM) has recently attracted great attention as a promising technology to further improve the transmission capacity and spectral efficiency. Very recently, SDM employing twisted lights, also known as orbital angular momentum (OAM) carrying lights, provides an alternative approach to increasing the transmission capacity and spectral efficiency of optical communications. …

The current global energy system is both unsustainable and inequitable, and large changes are required quite rapidly if there is to be any chance of limiting the effects of global warming. The global community has agreed on sustainable development goals attempting to integrate and balance the three dimensions of economic, …