Active Signal Propagation and Imaging Using Vortex Beams

Abstract

Abstract : The objective of this research project was to circumvent scattering obstacles for optical signal propagation and imaging through turbid media, making use of the phase singularity and orbital angular momentum of vortex beams. The specific aims of the project were: (1) Develop a guide-probe technique that guides the signal beam into turbid media with optical vortex beams, carrying orbital angular momentum. Unlike more conventional methods that have to bear the deteriorated scattered light, this innovative technique was based on the ability of an optical vortex guide beam to bore a transient viewing path in the medium. Imaging through this path experienced less obstacle scattering events and in turn enhanced contrast and resolution of the image. (2) Investigate the degradation of the orbital angular momentum by turbid media and the optical memory effect and evaluate its capability for providing discrimination against multiply scattered light and thus facilitating imaging through turbid media. (3) Investigate the ability to generate a tunable optical filter using optical vortex light in concert with supercontinuum and a novel liquid crystal q-plate