Localized dynamics arising from multiple flat bands in a decorated\n photonic Lieb lattice

Abstract

Photonic lattices have emerged as a promising approach to localize light in\nspace, for example, through topologically protected edge states and\nAharonov-Bohm caging. They are of particular importance in the study of flat\nband systems via the associated nondiffracting compact localized states.\nHowever, such states typically appear static, thus not allowing adaptive or\nevolutionary features of light localization. Here we report on the first\nexperimental realization of an oscillating compact localized state (OCLS). We\nobserve an oscillatory intensity beating during propagation in a\ntwo-dimensional photonic decorated Lieb lattice. The photonic system is\nrealized by direct femtosecond laser writing and hosts multiple flat bands at\ndifferent eigenenergies in its band structure. Our results open new avenues for\nevolution dynamics in the up to now static phenomenon of light localization in\nperiodic waveguide structures.\n