Customizable trajectory of trapped particle in quadruple-beam optical trap.

We have presented and demonstrated a customizable trajectory of a trapped particle in the Quadruple-beam optical trap. The orbital motion of the trapped microsphere was realized by modulating the trapping power. The motion trajectories could be designed by adjusting the modulation frequency, amplitude, and phase. By using this method, we have realized the triangle, bowknot, ellipse, straight line, and hooklike trajectories. The motion frequencies and circumferences were also modulated. The customizable trajectory in the optical trap may result in more possibilities for directional movement, microfluidic mixing, driven machines, and even painting freely.