Optical Bloch oscillations in waveguide arrays

Abstract

We show that optical Bloch oscillations can emerge in waveguide arrays with linearly varying propagation constants. The existence of localized modes (Wannier–Stark states) with equidistant wave-number spacing (Wannier–Stark ladder) that do not undergo diffraction is analytically proved. The evolution of arbitrary initial excitations is described, and potential applications are suggested.