Abstract
We demonstrated the generation of vortex beams using a GaAs-based ring-shaped Bragg reflector waveguide functioning as a highly dispersive angular diffraction element for potential applications in integrated mode-multiplexing in a multimode fiber. The polarization measurement of far-field patterns shows the formation of a radially polarized vortex beam. A tunable ring-shaped far-field pattern was demonstrated by tuning the wavelength of coupled light. We also integrated multi-ring vortex beam emitters, demonstrating the possibility of the creation and multiplexing of vortex beams with different orbital momentums. (C) 2014 The Japan Society of Applied Physics