Date of Award

3-9-2005

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Electrical and Computer Engineering

First Advisor

Matthew Goda, PhD

Abstract

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.

AFIT Designator

AFIT-GEO-ENG-05-02

DTIC Accession Number

ADA435223

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