WDM Free-Space Optical Communication System of High-Speed Hybrid Signals

A wavelength-division-multiplexing (WDM) free-space optical (FSO) communication system of a high-speed hybrid signal is proposed and demonstrated in this study. This study is the first to transmit a high-speed hybrid signal mixed with four wavelengths that are modulated with different signals, namely 10, 25, 28, and 32 Gb/s, using a single beam. Favourable bit error rate (BER) and clear eye maps are achieved by adopting parameters after investigating the bandwidth of tuneable optical bandpass filter, channel spacing, and number of mixed light channel effects on system performance. The WDM-FSO communication system of a high-speed hybrid signal has a simple configuration, low cost, and low BER.