2D optical wireless broadcasting system enabled by a liquid crystal on silicon and rotated-splitting-SLM algorithm

In this paper, a 2D optical wireless broadcasting system with low path loss is proposed and experimentally demonstrated based on a commercial liquid crystal on silicon (LCoS) device and rotated-splitting-SLM algorithm. The low path loss is realized by our designed pair of fiber collimators with large beam waist, which can significantly reduce the coupling loss. By using the proposed system and algorithm, a 60-Gb/s PAM-4 signal is successfully broadcasted over 2-km standard single mode fiber and 14 m free space link with 16 dB path loss for up to four mobile users. The experimental results reveal that the LCoS based on the proposed rotated-splitting-SLM method can be used for multi-user broadcasting in the high-speed in-building dynamic networks.