We propose a hybrid surface plasmonic waveguide structure containing a metal ridge with rounded corners and a special triangular air gap layer.The combination of this particular triangular structure and other materials effectively improves the performance of nano-lasers. We apply the finite element method and use COMSOL Multiphysics software to construct the two-dimensional and three-dimensional models,and use the modal analysis module to analyze the waveguide characteristics of the waveguide structure and ...