Defect solitons in kagome optical lattices.

We report the existence and stability of solitons in kagome optical lattices with a defect in photorefractive crystal under focusing saturable nonlinearity. For different types of defects, solitons will exist in different gaps. For a positive defect, the solitons only exist in the semi-infinite gap and only stably exist in the low power region. For a negative defect, the solitons exist both in the semi-infinite gap and the first gap. With an increasing of the negative defect depth, the stable region in the semi-infinite will be narrowed, while solitons will be firstly unstable in the high power region of the first gap, and finally solitons will be not stable in the whole first gap.