  Narrow-band filtering of light is widely used in optical spectroscopy. Atomic
filters, which rely on the Faraday effect, allow for GHz-wide transmission
spectra, which are intrinsically matched to an atomic transition. We present an
experimental realization and a theoretical study of a Faraday anomalous
dispersion optical filter (FADOF) based on cesium and its D$_1$-line-transition
($6^2S_{1/2}\rightarrow6^2P_{1/2}$) around 894nm. We also present the prospects
and visions for combining this filter with the single photon emission of a
single quantum dot (QD), which matches with the atomic transition.
