Laser induced fluorescence (LIF) diagnostic techniques1–3 allow investigation of diverse plasma phenomena. LIF techniques will be discussed in the context of a series of experiments carried out at UCI including: (1) phase space reconstructions of ion response to electron and ion beam generated modes,4,5 ion acceleration and anomalous transport in the near wake of plasma-obstacle systems, (2) optical tomographic techniques2 applied to ion acceleration in velocity space,6 and (3) optical tagging techniques used to quantitatively assess classical and turbulent models of cross-field particle diffusion.7 This work was supported by NSF Grants ♯PHY-8606081 and ♯ATM-8411189.