Observation of Defect-Free Surface Modes in Optical Waveguide Arrays

Abstract

We report on the experimental observation of novel defect-free surface modes predicted theoretically for modulated photonic lattices [I. L. Garanovich et al., Phys. Rev. Lett. 100, 203904 (2008)10.1103/PhysRevLett.100.203904]. We generate the linear surface modes in truncated arrays of periodically curved optical waveguides created in fused silica by a laser direct-writing technique. Our results demonstrate that the degree of surface wave localization can be controlled by selecting the waveguide bending amplitude.

Dynamic localization in Glauber–Fock lattices

“…In finite chains of coupled wells with uniform hopping rates the quasi-energy collapse is imperfect, and a pseudo-collpase is typically observed with a fine and generally complex structure of crossings and anticrossings of quasi-energies near the pseudo collapse point [26,27]. In a homogeneous semi-infinite lattice, the application of the sinusoidal force can give rise to dynamically-sustained surface states [28,29,33], which prevent quantum self imaging when the wave packet reaches the lattice boundary. As a general rule, DL in truncated or inhomogeneous lattices is only asymptotically realized in the high frequency regime, where the applied force basically yields a renormalization of the tunneling rate and the DL condition corresponds to the coherent destruction of tunneling between adjacent sites in the lattice [34].…”

Tamm–Hubbard surface states in the continuum

“…The direct observation of surface states in solids remained elusive for decades until the advent of semiconductor superlattices [5]. In optics, analogues of Tamm and Shockley surface states have been extensively studied for different types of photonic crystals and waveguide lattices [6,7,8,9,10,11], and the role of optical nonlinearities on surface wave localization has been highlighted by several authors (see, e.g., [12] and references therein). Surface electronic waves are generally regarded as bound states of the single-particle Schrödinger equation localized at the edge of a truncated periodic potential with an energy in a gap [13] (bound states outside the continuum, BOC).…”

Self-Action of Light Fields in Waveguide Photon Structures Based on Electro-Optic Crystals

“…The behavior of the light fields near the interfaces between the stationary periodic waveguide structures with different parameters in the LiNbO 3 crystal was investigated both theoretically and experimentally [45]. The special features of manifestation of linear and nonlinear discrete light diffraction in photonic structures with curved waveguide elements in LiNbO 3 were demonstrated in [46]. Spatial optical modulation of the parameters of stationary waveguide structures caused by the photorefractive properties of the material provides additional possibilities for investigation of effects of the interaction of wave packets with complex photonic structures.…”