Huang, K., Liu, H., &amp; Teng, J. (2021). Broadband generation of rational-order optical vortices using a bilateral meta-grating. Journal of Optics, 23(2), 024002. doi:10.1088/2040-8986/abe01e
Optical vortices usually carry integer orbital angular momentum (OAM) of light.
Recently, optical vortices with rational-order OAMs have also been created continuously
for entangling the super-position OAM states of monochromatic light in a single device.
Here, we report the broadband generation of such rational-order optical vortex beams
by using a bilateral meta-grating. The meta-grating contains two oblique gratings that
encode two sign-opposite linear phase profiles in two symmetric sides, thus leading to
phase dislocation along the symmetric axis. We reveal that the encoded phase profiles are
valid in a range of wavelengths due to the broadband response of the meta-grating. The
measured phase, intensity and tilting angles match perfectly with theoretical prediction,
suggesting the bilateral meta-grating as a powerful device to create broadband and
continuous OAM of light for various applications such as optical micro-manipulation,
optical communication, quantum physics, and super-resolution imaging.
There was no specific funding for the research done
This is the Accepted Manuscript version of an article accepted for publication in Journal of Optics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/2040-8986/abe01e