{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Scattering Cross Section of a Finite Dielectric Cylinder\n", "\n", "As an alternative to the \"ring\" sources of the previous examples, it is also possible to launch planewaves in cylindrical coordinates. This is demonstrated in this example which involves computing the scattering cross section of a finite-height dielectric cylinder. The results for the 2d simulation involving the cylindrical $(r,z)$ cell are validated by comparing to the same simulation in 3d Cartesian coordinates which tends to be much slower and less accurate at the same grid resolution.\n", "\n", "The calculation of the scattering cross section is described in [Tutorial/Basics/Mie Scattering of a Lossless Dielectric Sphere](https://meep.readthedocs.io/en/latest/Python_Tutorials/Basics/#mie-scattering-of-a-lossless-dielectric-sphere) which is modified for this example. A linearly-polarized planewave is normally incident on a $z$-oriented cylinder which is enclosed by a DFT flux box. Expressed in cylindrical coordinates, an $x$-polarized planewave propagating in the $z$ direction is the sum of two circularly-polarized planewaves of opposite chirality:\n", "\n", "