Light diffracting to different diffraction orders of a periodic grating generally propagates along a set of straight trajectories. Here we show that certain quasi-periodic gratings can produce curved diffraction orders. These curved lobes are created by the caustic interference of the originally straight diffraction orders and manifest themselves as accelerating beams. Both numerical simulations and experimental results demonstrate the validity of multiple accelerating beam generation with a single binary grating. Our work makes a quantitative link between the quasi-periodicity of a grating and the resulting caustic diffraction orders. Furthermore, the use of binary devices has important applications in acoustics, x-ray optics, and electron beam engineering and is also useful when high optical power is needed.
© 2013 Optical Society of America
Diffraction and Gratings
Original Manuscript: April 15, 2013
Revised Manuscript: June 24, 2013
Manuscript Accepted: July 4, 2013
Published: July 29, 2013
Nan Gao, Hailiang Li, Xiaoli Zhu, Yilei Hua, and Changqing Xie, "Quasi-periodic gratings: diffraction orders accelerate along curves," Opt. Lett. 38, 2829-2831 (2013)