Testing the accuracy and convergence of scattering calculations using Lorentz reciprocity

We present a simple and versatile approach to test the accuracy of scattering calculations. Based on the Lorentz reciprocity relation, this criterion can be used for any scattering object, especially where a reference solution (e.g. from Mie theory) does not exist. Application examples with arbitrary shape scatterers in plasmonic metals and high-index dielectrics numerically demonstrate the suitability of the technique, which can be utilized with any numerical method to increase the accuracy of the produced results.