Beam‐Steering Techniques for Indoor OWC
Ton Koonen · 2025
Optical beam-steering techniques for short-reach indoor optical wireless communication (OWC) systems are reviewed, deploying active or passive steering modules. Passive diffractive modules are explored, which steer multiple narrow beams individually in two dimensions downstream from a central ceiling unit to multiple users, establishing high-capacity connections at high user density. Each beam is two-dimensionally (2D)-steered by tuning the wavelength of its data signal. The system is readily scalable to serve more users by just feeding more wavelengths to the beam steerer. The data signals are generated remotely by tunable laser diode transmitters, which greatly facilitate system upgrades. Two options are analyzed in depth: semi-continuous steering using a pair of crossed diffraction gratings, and discrete steering using an arrayed waveguide grating wavelength demultiplexer with a 2D arrangement of its output ports. For upstream, continuous beam steering deploying a 2D electromechanical translator stage is investigated. For this, laser diodes with an arbitrary wavelength are used, minimizing the costs of the user terminal.