Coherent detection in self-homodyne systems with single and multi-core transmission

Abstract

This work reviews the latest advancements in coherent self-homodyne detection (SHD) using signals with polarizationor space-multiplexed pilot tones (PTs) originating from the same light source, towards the implementation of low-cost coherent receivers. The coherency between signals and PTs drastically reduces laser linewidth requirements, enabling the use of high-order modulation formats with low-cost DFB lasers. In this work, we revise the application of SHD in high-capacity space-division multiplexed links using multi-core fibers, outlining optical signal-to-noise ratio, skew and phase noise requirements of such systems. Furthermore, we evaluate the application of SHD for the implementation of laser-less optical network units in passive optical networks, as well as recent developments in digital SHD techniques.