Dynamics of a complex plasma measured with a 3D light field camera

Abstract

The dynamics of a single-layer complex plasma crystal was measured by performing its three-dimensional (3D) imaging with a light field camera. To enrich the crystal's dynamics, the mode-coupling instability (MCI) was triggered in it by lowering the discharge power below a threshold. 3D coordinates of all particles in the crystal were extracted from the recorded video. All three fundamental wave modes of the plasma crystal were calculated from the particle velocity. In the out-of-plane spectrum, only the MCI-induced hot spots (corresponding to the unstable hybrid mode) were resolved. Both longitudinal in-plane and out-of-plane wave modes show profound anisotropy. The results are in agreement with theory and simulations and show that light field cameras can be used to measure 3D dynamics of complex plasmas.