A new contour-integation algorithm for general nonlinear eigenvalue problems is proposed. The algorithm has the advantage of returning only physically relevant eigenvalues that couple to external fields. JCMsuite is used to solve the scattering problems lying on the contour.
F. Binkowski, et al. A Riesz-projection-based method for nonlinear eigenvalue problems. Journal of Computational Physics, 419, 109678 (2020).