Hybrid transmission of unicast and broadcast signals without optical filter for WDM systems

摘要

This paper proposes and experimentally demonstrates the hybrid transmission of unicast and broadcast signals without using optical filters for the WDM systems. The dual-wavelength generated from a laser source are modulated by a phase modulator (PM) with a broadcast signal. Then, the central carriers and side-bands are separated by using a polarization beam splitter (PBS) and modulated with unicast data using Mach-Zender modulator (MZM). After combining side-bands (broadcast data) and central carriers (unicast data) using PBS, the hybrid data are transmitted through 25 km single mode fiber (SMF) to the remote node (RN). By probably adjusting the polarization controller (PC), the central carriers and side-bands are separated by PBS into two orthogonal polarization states. After transmission over 25 km SMF, the measured bit error rate (BER) curves and eye diagrams show that the performance of the proposed system is excellent to simultaneously transmit both unicast and broadcast signals. Moreover, only two modulators are required, which is cost-effective and also FBG or optical filter is not required due to sensitivity to temperature that decreases the system stability.