Defect-free surface waves

A recent study revealed that boundaries of modulated photonic lattices produced a new type of surface wave without any introduced or induced surface defects. Nontrivial modification of the diffraction properties of the lattice edge introduced by the lattice modulation caused the appearance of these novel surface modes. This study helped to develop a general analytical theory of novel surface modes and demonstrated their unique properties. The femtosecond laser direct-writing technique to create periodically curved waveguide arrays in silica glass samples was used for this study. A special type of silica with high OH content was also used, which caused the formation of fluorescent color centers during the writing process. Generation of these surface waves in optics opened new opportunities for the development of tools for studying various surface phenomena.