Design of bottle beam based on dual-beam for trapping particles in air

An optical system structure, consisting of a tunable bottle beam, was designed to capture micron absorbing particles in air. Using a 670 nm semiconductor laser as the light source, a bottle beam was formed with beam shaping elements, a double-axicon lens, and parabolic annular mirrors. Taking a particle of carbon nanoclusters as an example, the capturing effect of the bottle beam on a particle was analyzed. By adjusting the size of the bottle beam, the capture performance for particles of different radii could be optimized. When the optical power of the conical doughnut hollow beam was P=0.05  W, the composite bottle beam could capture a particle of carbon nanoclusters smaller than 237 μm.