Preliminary results from the laser system generating quasi 3-D ellipsoidal photocathode laser pulses at PITZ

The optimization of photoinjectors is crucial for the successful operation of linac-based free electron lasers, and beam dynamics simulations have shown that 3D ellipsoidal photocathode laser pulses result in significantly lower electron beam emittance than that of conventional cylindrical pulses. Therefore, in collaboration with the Institute of Applied Physics (Nizhny Novgorod, Russia) and the Joint Institute of Nuclear Research (Dubna, Russia), a Laser system capable of generating quasi 3-D ellipsoidal laser pulses has been developed and installed at the Photo Injector Test facility at DESY, Zeuthen (PITZ). The pulse shaping has been realized using the spatial light modulator technique, characterized by cross-correlation measurements, and is going to be demonstrated by electron beam measurements. In this contribution the overall setup, operating principles, and initial results of the new photocathode laser system at PITZ will be reported.