  We investigate the possibility of measuring the homogeneous and inhomogeneous
contribution to the linewidth of a spectrally diffusing single photon emitter
using a simple photon correlation spectroscopy method (PCS). The photon energy
statistics of the homogeneous line (poissonian) and of the spectral diffusion
(first order markovian) being of different natures, they act differently on the
half-line autocorrelation function (HLAF). We model here their effects and show
it is possible to extricate them, opening the opportunity to determine
separately the homogeneous linewidth, and the spectral diffusion amplitude.
