title: Fraunhofer diffraction of a partially blocked spiral phase plate.
abstract: The Fraunhofer diffraction pattern from a partially blocked spiral phase plate (SPP) produces a partial vortex output pattern that is rotated by 90 degrees compared with the input. The rotation direction depends on whether the angular phase pattern increases in the clockwise or counterclockwise direction. In this work, we present an explanation of this effect based on careful examination of classical diffraction theory and show new experimental results. This approach is very convenient for easily determining the sign of the vortex charge.
authors: Department of Physics, San Diego State University, San Diego, California 92182-1233, USA.
authors: Don M
authors: DM
authors: Cottrell
authors: Jeffrey A
authors: JA
authors: Davis
authors: Travis J
authors: TJ
authors: Hernandez
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008962:Models, Theoretical; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity