Laser generated ultrasound has gained interest as an alternative source of ultrasound thanks to its remote operation, high resolution in the excitation area and broad frequency band. However, one of its drawbacks is the wide-angle directivity. We present a numerical study where the directivity of ultrasound propagation is controlled by the insertion of a phononic crystal in the ultrasound propagation path. This crystal collimates the laser generated ultrasound at he desired frequency band in metalllic structures and reduces perturbations in the detected wavefront, for more accurate signal processing.