The High Field Science (HFS) group at the Center for Ultrafast Optical Science (CUOS) is a world-leading group researching the science and applications of relativistic plasma. In High Field Science we are engaged in a number of ongoing key research projects involving the generation of relativistic plasmas, including table-top acceleration of high peak energy electron beams using plasma bubbles, acceleration of high quality energetic ion beams, the generation of high brightness x-ray pulses and laser driven neutron sources, in addition to numerical modeling of laser-plasma interactions. We are also involved with other studies, ranging from the investigation of phenomena related to generating fusion energy using lasers, to the use of laser-plasmas to study astrophysical phenomena. In addition, we are working on the development of ultra-high power laser technology.