Steven R. Mawhorter

Active Optical Tracking with Spatial Light Modulators Steven R. Mawhorter

Two spatial light modulators (SLMs) are utilized for beam splitting, steering and tracking. Both linear and holographic phase screens are used in a demonstration of technology to allow real time tracking to communicate in a one-to-several type scenario. One SLM is used to apply a linear phase modulation to steer multiple beams onto a detector. The spots that are produced represent the targets as they move around the field of view of the central communication node. A Gerchberg-Saxton algorithm will subsequently use the detected spots as the desired pointing locations. Using this as input, the Gerchberg-Saxton algorithm yields a phase only map for multiple spot beam steering which is called the holographic phase. The holographic phase screens are then used on a second SLM to steer beams onto the same detector in near real time. As the target spots move about the detector's field of view, the holographic spots track them.