Optical Zener-Bloch oscillations in binary waveguide arrays

PACS. 42.65.Sf – Dynamics of nonlinear optical systems; optical instabilities, optical chaos and complexity, and optical spatio-temporal dynamics. Abstract. – Zener tunneling in a binary array of coupled optical waveguides with transverse index gradient is shown to produce a sequence of regular or irregular beam splitting and beam recombination events superimposed to Bloch oscillations. These periodic or aperiodic Zener-Bloch oscillations provide a clear and visualizable signature in an optical system of coherent multiband dynamics encountered in solid-state or matter-wave systems. Light propagation in waveguide arrays has provided in the past few years a conceptually and experimentally relevant model to study the optical analogue [1–8] of Bloch oscillations (BO) and related effects typically encountered in solid-state or matter-wave systems [9, 10]. One of the major advantages offered by waveguide arrays as compared to other optical systems [11] is the possibility to easily perform a direct visualization of the wave packet dynamics in coordinate space [6] which is complementary to most usual frequency-domain (spectral) measurements [9,11]. Recent experiments in waveguide arrays [6,8] have reported the beautiful observation of optical Zener tunneling (ZT), thus motivating the study of multiband