| Summary: | We propose and demonstrate a new method for creation of fan-shaped optical vortex beams by rational phase modulation and assembly based on a well-known conical vortex phase. Our design is different from the previously proposed method for generation of power-exponential vortex beams. Such unconventional vortex beams consist of multiple spiral beam filaments (as the fan blades), and their overall beam size and spiral angle can be readily controlled by adjusting the parameters. Experimentally, two examples of applications are illustrated with such fan-shaped vortex beams: one is optical clearing through densely scattering particle suspensions; the other is optical shielding and transporting a target particle from the suspensions by adding a donut pattern in the center (as the fan head). We envisage such specially designed fan beams may be used as a multifunctional tool for microfluidic and biological applications that involve the complex environment of the living bodies, especially for active isolation or separation of a trapped particle from fluid environments of high particle concentrations.
|
|---|
