Date of Award
Master of Science
Department of Electrical and Computer Engineering
Matthew Goda, PhD
Optical Phased Array (OPA) technology offers advantages in the reduction of size, weight, and power of optical steering devices. Nematic liquid crystal (LC) spatial light modulators (SLMs) have been studied as a potential candidate for building non-mechanical OPAs. They can steer a laser beam and split the beam into multiple beams. This thesis builds upon the prior research showing each split beam can be individually controlled, including variation in intensity. A closed loop tracking scenario shows the flexibility of the SLM by tracking and stabilizing an incoming beam. Results show that applying a phase grating to the SLM has limitations with diffraction and fringing when the SLM is divided into sub-apertures during beam splitting, forcing trade-offs in performance. An iterative Fourier transform algorithm is proposed to overcome the limitations by creating a phase hologram that steers and splits the beam without subdividing the SLM, seeking to minimize the aforementioned effects by allowing more efficient use of the LC array. Results show the beam can be split and steered by a phase hologram and is compared to simulation and the phase grating technique.
DTIC Accession Number
Perry, Michael J., "Using Liquid Crystal Spatial Light Modulators for Closed Loop Tracking and Beam Steering with Phase Holography" (2005). Theses and Dissertations. 3876.