  Exceptional points are complex branching singularities of non-Hermitian bands
that have lately attracted considerable interest, particularly in non-Hermitian
photonics. In this article, we review some recent developments in non-Hermitian
photonic platforms such as waveguides, photonic crystals, Fabry-Perot
resonators and plasmonic systems, and suggest how optical non-linearities and
exceptional bound states can significantly impact the development of
non-Hermitian photonics in the near future.
