Our intention for the site is plain and simple: provide electrodynamic problems with solutions. We hope that the information may help one or the other to **understand photonics**. We believe that the best way to achieve this is to **solve problems** and have their **solutions** at hand. We also take the chance to supply additional information in the **background section** for most of the problems. This might be an explanation of a **related research** topic or more in-depth information. We hope you enjoy your path to understand photonics!

We will calculate the first three multipole moments of a **deformed charged sphere**. Such a charge distribution is often used to **model nuclei** and understand their stability. The **rotational symmetry** of the problem will ease our computations significantly.

One of the **basic problems** of magnetostatics is the infinite wire. Using the several **symmetries** of the **current distribution** we will be able to not only find the **magnetic field** - we will also verify the "**right-hand rule**".

**Single-photon-sources** are extremely desirable devices as they can enable **quantum-secure communication**. But to enable a fast information exchange, a tradeoff between quantity and quality of the photons has to be considered.

Devices composed of qubits and a suitably designed nanoantenna might be used for quantum computation. They should not only be much faster than any known implementation but also extremely small.

]]>**Graphene** is a two-dimensional material with extraordinary properties. Its **tunable conductivity** makes the material a prime candidate for sophisticated light-matter interactions. We will see how graphene antennas can be used to dictate a molecule's emission frequencies

With the freely available interactive FDTD toolbox you can **simulate and visualize** the electromagnetic field in a structured material such as a **photonic crystals**, **waveguides** or investigate **refraction** at dielectric boundaries and diffraction in **free space**.