title: Observation of in-band lattice solitons.
abstract: We report the first experimental and theoretical demonstrations of in-band (or embedded) lattice solitons. Such solitons appear in trains, and their propagation constants reside inside the first Bloch band of a square lattice, different from all previously observed solitons. We show that these solitons bifurcate from Bloch modes at the interior high-symmetry X points within the first band, where normal and anomalous diffractions coexist along two orthogonal directions. At high powers, the in-band soliton can move into the first band gap and turn into a gap soliton.
authors.affiliation: Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA.
authors.forename: Xiaosheng
authors.initials: X
authors.lastname: Wang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Chen
authors.forename: Jiandong
authors.initials: J
authors.lastname: Wang
authors.forename: Jianke
authors.initials: J
authors.lastname: Yang