We experimentally demonstrate linear bandgap guidance of optical vortices as high-gap defect modes (DMs) in two-dimensional induced photonic lattices. We show that donut-shaped vortex beams can be guided in a tunable negative (lower-index) defect, provided that the defect strength is set at an appropriate level. Such vortex DMs have fine features in the “tails” associated with the lattice anisotropy and can be considered as a superposition of dipole DMs. Our numerical results find good agreement with experimental observations.
© 2010 Optical Society of America
Diffraction and Gratings
Original Manuscript: March 12, 2010
Revised Manuscript: May 28, 2010
Manuscript Accepted: June 1, 2010
Published: June 14, 2010
Daohong Song, Xiaosheng Wang, Daniel Shuldman, Jiandong Wang, Liqin Tang, Cibo Lou, Jingjun Xu, Jianke Yang, and Zhigang Chen, "Observation of bandgap guidance of optical vortices in a tunable negative defect," Opt. Lett. 35, 2106-2108 (2010)