?
Observation of Linear and Nonlinear Light Localization at the Edges of Moiré Arrays
We observe linear and nonlinear light localization at the edges and in the corners of truncated moire ́ arrays created by the superposition of periodic mutually twisted at Pythagorean angles square sublattices. Experimentally exciting corner linear modes in the femtosecond-laser written moire ́ arrays we find drastic differences in their localization properties in comparison with the bulk excitations. We also address the impact of nonlinearity on the corner and bulk modes and experimentally observe the crossover from linear quasilocalized states to the surface solitons emerging at the higher input powers. Our results constitute the first experimental demonstration of localization phenomena induced by truncation of periodic moire ́ structures in photonic systems.