  The generation of entangled photon pairs by parametric down--conversion from
solid state CW lasers with small coherence time is theoretically and
experimentally analyzed. We consider a compact and low-cost setup based on a
two-crystal scheme with Type-I phase matching. We study the effect of the pump
coherence time over the entangled state visibility and over the violation of
Bell's inequality, as a function of the crystals length. The full density
matrix is reconstructed by quantum tomography. The proposed theoretical model
is verified using a purification protocol based on a compensation crystal.
