  We present a simple method to extract the homogeneous linewidth of a single
photon emitter line exhibiting fast (down to 1 ns) spectral diffusion (SD). It
is based on a recently developed technique using photon correlation
measurements on half of the line. Here we show that the SD induced bunching
depends on the ratio between the width of the homogeneous line and the spectral
diffusion amplitude. Using this technique on a CdSe/ZnSe quantum dot, we
investigate the temperature dependence of its fast SD amplitude and its
homogeneous excitonic linewidth.
