Efficient vortex beam generation using gradient refractive-index microphase plates. Academic Article uri icon


  • Vortex beams were theoretically demonstrated by patterning a fiber facet with $N$-segment microphase plates. By changing the aluminum oxynitride material composition of each segment, gradient refractive-index phase plates (GRPs) were designed and introduced a ${{2}}pi l$ azimuthal optical phase difference. The gradient index profile was able to convert a fiber Gaussian mode to a Laguerre-Gaussian mode with varieties of topological charge $l$. A three-dimensional finite-difference time-domain method was applied to calculate the near-field optical phase maps and the far-field beam profiles projected from the micro-GRPs. A uniform vortex beam with a symmetrical doughnut shape was obtained by optimizing the GRPs' radii and the number of segments. The micro-GRPs enabled flat optical components for efficient vortex beam generation.

published proceedings

  • Appl Opt

author list (cited authors)

  • Zhou, J., & Lin, P. T.

citation count

  • 1

complete list of authors

  • Zhou, Junchao||Lin, Pao Tai

publication date

  • May 2021