It's a basic characteristic that there exists a phase singularity located at the center for pure vortex light. If combining several vortex lights belonging to the same eigenmode set, the central hi…
Broadband generation of orbital angular momentum (OAM) beam in fiber has a lot of applications in optical communications and fiber sensing. However, the efficient broadband generation of second-ord…
There are great challenges in the generation of higher-order modes for long period fiber grating (LPFG). The cross-coupling coefficient between the fundamental mode and the higher-order azimuthal m…