  High-speed optical wireless communication can address the exponential growth
in data traffic. Adaptive beamforming customized for the target location is
crucial, but existing solutions such as liquidcrystal spatial light modulators
and microelectromechanical systems require costly micro/nano manufacturing,
delicate alignment, and a high degree of mechanical stability. These challenges
reflect the fragility of integrating a fiber network with micro/nano mechanical
or photonic systems. Here, we realize low-cost, low-loss, and fiber-compatible
beamforming and continuous beam steering through controlled bending of a
multi-mode fiber that modifies its modal coupling, and use it to enable
flexible optical wireless communication at 10 Gb/s. By using the fiber modal
coupling as degrees of freedom rather than an impediment, this approach offers
a promising solution for flexible and cost-effective optical wireless
communication networks.
