Michael Liu, IfA/Hawaii "Extrasolar Planetary Systems at High Angular Resolution" Abstract: Detection and characterization of extrasolar planetary systems demand a challenging combination of both high angular resolution and high contrast. New adaptive optics (AO) studies on the largest ground-based telescopes can meet this challenge. We discuss AO studies of the evolution of young debris disks (the extrasolar analogs of the young Kuiper Belt) and of direct detection of young massive planets. For the latter, our team has been selected to carry out an extensive multi-year search to directly image extrasolar planets around other stars using the new high contrast imager NICI at the Gemini-South Telescope. Our NICI Planet-Finding Campaign is expected to be the largest and most sensitive imaging survey to date for massive (~1 Mjup) planets around other stars.