Optical trapping and manipulation of single particles in dusty plasma

Current methods of laser manipulation in dusty plasma mostly focus on manipulating groups of particles suspended in the plasma sheath to probe collective dust-dust interactions. In this work, we report on single particle trapping and manipulations in a rf dusty plasma using the optical trapping technology. A recently-developed universal optical trap (UOT) is integrated with a rf Argon or Argon/air plasma that operates in the pressure range of tens – hundreds of millitorr, at 1-10 W. Single wall carbon nanotube particles, for the initial technology demonstration, are introduced individually into the plasma and becomes trapped by the balance of the optical force, the Coulomb force, and the gravitational force. Results show that the UOT can not only trap a single particle, but also walk the trapped particle to different locations in the dusty plasma, becoming an effective probe of both sheath and plasma properties. The particle's trapping status such as its steady state and motion dynamics is monitored in real time by an embedded imaging system. Optical configurations and plasma operating conditions, which affect the particle trapping and manipulations, are also explored.