Self-Homodyne Coherent Optical Communication System – A Review

Short reach communication like data center interconnects are looking for increased data rate schemes to satisfy the high speed and low power consumption requirements. In this paper, some schemes that utilize the self-homodyne links for transmission which allows the system to transmit the carrier signal information and modulated signal through the same optical channel are explained. One of the schemes includes stokes vector direct detection (SV-DD) for the linear complex channel, which states of giving 100% spectral efficiency and elimination of photodetection nonlinearity. The next scheme reviewed is a system involving space division multiplexing (SDM) transmission for high capacity using an SH link in multicore fiber (MCF), which investigate the phase noise cancellation for KHz-MHz range linewidth for quadrature phase-shift keying (QPSK) and 16-level quadrature amplitude modulation (16-QAM). High capacity DCI using polarization multiplexed signal and LO less receiver scheme is investigated as to provide the high data with effective increment in system capacity as compared to pulse amplitude modulation (PAM-4) scheme, and less amount of DSP at the LO-less receiver.