Coherent optics everywhere: a new dawn for photonic networks
The widespread adoption of the Internet and its influence on our daily life is unquestioned. Global Zettabyte traffic has rendered photonics as indispensable for the communication infrastructure. While direct signal detection has been dismissed in radio communications decades ago, it prevails in short- and medium-reach optics in virtue of its simplicity. In such an environment photonics can only rely on incremental improvements, whereas it desperately seeks for disruptive concepts.
COYOTE envisions a novel coherent homodyne transceiver concept for analogue signals and access to higher-order formats with efficiencies of 10 bits/symbol. On top of this, high-fidelity transport of multi-band 5G radio signals in the millimetre-wave range up to 100 GHz will be enabled by analogue coherent photonics while mitigating energy-hungry digital signal processing. COYOTE takes one more leap and dares the contradictory full-duplex data transmission in virtue of its novel reception engine to ultimately guarantee a lean solution with greatly simplified yet flexible “hardware”. 
The key asset of COYOTE’s coherent engine will be a locked laser with improved coherence characteristics together with a flexible modulator-detector element, which is capable to emulate direct-detection systems in a transparent way while giving birth to novel networking concepts. Exploration of the 3D Stokes and 2D quadrature spaces through a segmented receiver architecture will boost the spectral efficiency to >10 bits/s/Hz.
It is the lean and yet efficient coherent transceiver methodology of COYOTE that will remove the currently existing boundary between direct-detection and coherent systems in the midst of network reaches. By coherently “reviving” these telecom segments of integrated wireline-wireless access networks, optical interconnects for intra-datacentre connectivity and even quantum communication, an order-of-magnitude improvement in terms of spectral efficiency x reach product will be gained.