Nonlinear Mode Coupling in a 1D Dusty Plasma

We report experimental findings on the excitation and nonlinear interaction of collective modes in a 1D dusty plasma system. The dusty plasma is produced by introducing mono-dispersive Melamine Formaldehyde particles in the background of a capacitively coupled radio frequency (RF) Argon discharge in the Capacitively Coupled Dusty Plasma Experimental (CCDPx) device. A uniquely designed lower electrode, that can dynamically modify the transverse confining potential of the electrode, is used to form a 1D chain of dust particles. Collective oscillations are excited by applying an oscillatory radiation force on the particles using a tuneable laser. The dynamics of the dust particles are recorded using a high-speed optical imaging system, and the trajectories of the individual particles are tracked using Particle Tracking Velocimetry (PTV) tools. The nature of coupling between the different modes is estimated from kinetic level measurements using bi-spectral and bi-coherence analyses. The experimental findings, covering a wide parameter regime, are then compared with classical molecular dynamics simulations that assume a Yukawa interaction among the particles in order to provide useful physical insights into some of the observed novel features of the nonlinear phenomena.