We first present a bidirectional beam propagation method (BiBPM) based on axially symmetric full-vectorial finite element (Axi-FVFEM). The Axi-FVFEM BiBPM is more versatile than previous scalar for axi-symmetric structure. It has potential to offer efficient analysis widely used FEM or difference techniques, especially large scale waveguide such as long periodic An air gap in an and fibre Bragg...

Minimax problems have gained tremendous attentions across the optimization and machine learning community recently. In this paper, we introduce a new quasi-Newton method for minimax problems, which call J-symmetric method. The is obtained by exploiting structure of second-order derivative objective function in problem. We show that Hessian estimation (as well as its inverse) can be updated rank...