Drive laser system for sparc photoinjector

In this paper we report the progress of the SPARC photoinjector laser system. In the high brightness photoinjector the quality of the electron beam is directly related to the photocathode drive laser. In fact the 3D distribution of the electron beam is determined by the incoming laser pulse. The SPARC laser is a 10 Hz frequency-tripled TW-class Ti:Sa commercial system. To achieve the required flat top temporal shape we perform a manipulation of the laser spectrum in the fundamental wavelength and in the third harmonic. The optical transfer-line has been implemented to limit the pointing instabilities and to preserve to the cathode the temporal and spatial features of the laser pulse. We present the recorded performances in terms of time pulse shape and rf-to-laser synchronization.