Heinrich, M.M.HeinrichSzameit, A.A.SzameitDreisow, F.F.DreisowKeil, R.R.KeilMinardi, S.S.MinardiPertsch, T.T.PertschNolte, S.S.NolteTünnermann, A.A.TünnermannLederer, F.F.Lederer2022-03-042022-03-042009https://publica.fraunhofer.de/handle/publica/21928710.1103/PhysRevLett.103.113903We report on the generation of three-dimensional discrete X waves in a femtosecond laser-written waveguide array. Our measurements constitute the first experimental observation of temporally localized three-dimensional discrete-continuous entities. The X waves spontaneously emerge from a single-site excitation due to the discrete diffraction of the lattice and the normally dispersive as well as cubically nonlinear properties of the fused silica used as host material.endiffraction-freefused silicaguide arraysolution620530journal article