Enhanced nonlinear optical responses of graphene in multi-frequency topological edge modes Guo, Jun ; Wang, Haotian ; Dai, Xiaoyu ; Xiang, Yuanjiang ; Tang, Dingyuan Abstract Publication: Optics Express Pub Date: October 2019 DOI: 10.1364/OE.27.032746 Bibcode: 2019OExpr..2732746G