Klein tunneling of light in waveguide superlattices

We present an experimental observation of Klein tunneling of light waves in lattices of evanescently coupled waveguides with a superimposed potential step. The incident wave packet mass which is a characteristic feature of Klein tunneling is generated by a minigap in the band structure of the lattice. We studied different masses and measured the tunneling rates across the potential step. Copyright (C) EPLA, 2012