Multiple Structured Electromagnetic Waves Containing Orbital Angular Momentum for Novel Communications, Imaging, and Directed Energy
Abstract
Beams of light, indeed all electromagnetic waves, can carry orbital angular momentum (OAM).An OAM beam is uniquely structured, such that the spatial phase front ~twists~ in a helicalfashion as it propagates, and different rates of phase change form a set of orthogonal modes.Utilizing multiple EM waves with different OAM values has been relatively unexplored, with arich set of basic research challenges that has the potential to dramatically impact multiple DoDdisciplines. Each different OAM beam has a uniquely structured phase front and a centralintensity null that are sensitive to disruption by interacting with each other and with matter. Wewill explore using multiple OAM beams: (i) simultaneously for capacity/local power gain frommultiplexing, or (ii) sequentially for diversity gain using multiple unique measurements. Ifsuccessful, new knowledge and >10X performance enhancements will be achieved.Our curiosity-driven and focused scientific study includes: (i) mechanisms for minimizing andmaximizing the linear and nonlinear interactions among beams and with different types of matter(air, objects, sub-wavelength structures); and (ii) dependencies of OAM modal structures underharsh conditions. We will investigate: (a) the complex OAM spectrum; (b) interaction ofstructured beams with matter; (c) temporal/spatial characterization in nonlinear media, and (d)extraction/quantification of OAM signatures produced during interaction. We will exploretailoring of the beams~ structure and methods for signature analysis/recovery.We will examine proof-of-concept capabilities, including: (a) Communications: Capacity can bemultiplied by simultaneously transmitting multiple beams, and the beams~ can be tailored to limiteavesdropping. (b) Imaging: multiple structured beams can improve measurement sensitivity tosub-diffraction-limited resolution, and (c) Directed energy: different modes can be combinedcoherently to form spatial patterns with localized >10X intensity gain.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 23, 2016
- Source ID
- N000141612813
Entities
People
- Alan E. Willner
Organizations
- Office of Naval Research
- United States Navy
- University of Southern California