Reconfigurable and multiple beam steerable non-orthogonal-multiple-access system for optical wireless communication

The ability to reconfigure and adapt to different application scenarios plays an important role in future wireless communication systems. Here, a beam dividable and steerable optical wireless communication (OWC) system adopting a spatial light modulator (SLM) is presented. The reconfigurable multiple beam splitter as well as the adjustable splitting ratio are demonstrated. Experimental results show the proposed system can nearly evenly partition the input beam into up to five spots and can have the adjustable splitting ratio for the two-spot case. Combining non-orthogonal multiple access (NOMA) and wavelength division multiplexing (WDM), the proof-of-concept experimental demonstration shows the proposed system can provide 320.08 Gbit/s and 179.68 Gbit/s for the single-user scenario without beam steering and with steering of about 4°, respectively. Moreover, the data rates pairs of (92.20 Gbit/s, 119.17 Gbit/s) and (51.50 Gbit/s, 124.78 Gbit/s) can be achieved for the two-user scenario at different beam steering angles, respectively. The flexibility of data rate allocation for multiple users is also discussed. The OWC system under evaluation can satisfy the pre-forward error correction bit-error rate limit (pre-FEC BER = 3.8 × 10⁻³).