We have studied how coupling together a 2 dimensional photonic crystal (2D PC), made in a SOI wafer, and a Bragg mirror could modify the light properties of the light emitted by the 2D PC. By finely tuning the distance separating the Bragg mirror and the 2D PC with a piezo-electric set-up, we have recorded a modulation of the extracted intensity as well as of the quality factor of the structure (Q). These measurements are in agreements with 2D FDTD calculations. We explain them by the coupling of the 2D PC mode to Fano resonances created by the interferences of this mode with the pseudo radiative continuum