Invited Article: Direct phase mapping of broadband Laguerre-Gaussian metasurfaces
Abstract
We report on the fabrication of metasurface phase plates consisting of gold nanoantenna
arrays that generate Laguerre-Gaussian modes from a circularly polarized Gaussian
input beam. The corresponding helical phase profiles with radial discontinuities
are encoded in the metasurfaces by the orientation of the nanoantennas. A commonpath
interferometer is used to determine the orbital angular momentum of the generated
beams. Additionally, we employ digital holography to record the detailed phase
profiles of the Laguerre-Gaussian modes. This method allows a simple and direct quantitative
comparison of the measured phase profiles of the generated Laguerre-Gaussian
beams with the theoretically expected phase profiles. Experiments with different laser
sources demonstrate the broadband operation of the metasurfaces
Keywords
Gaussian distribution, NanoantennasPersistent identifier
http://hdl.handle.net/11012/85365Document type
Peer reviewedDocument version
Final PDFSource
APL Photonics. 2018, vol. 3, issue 11, p. 110803-1-110803-7.http://dx.doi.org/10.1063/1.5049368