An optical device, optical system, and method of generating optical beams
having high angular momenta are provided. The optical device includes a
whispering gallery mode resonator defining a resonator radius and an
elongated waveguide having a length defined between a first end and a
second end of the waveguide. The waveguide defines a waveguide radius
which increases at least along a portion of the length of the waveguide
in a direction from the first end to the second end. The waveguide radius
at the first end of the waveguide is smaller than the resonator radius
and the resonator is integrally formed with the first end of the
waveguide.