Experimental Investigation of Spiral Beam Formation by Binary Spiral Axicons.

In this paper, we demonstrate the possibility of generating spiraling light beams using binary spiral axicons. The influence of the laser wavelength and the axicon numerical aperture on the shape and size of generated spiraling beams is investigated experimentally. We have shown experimentally the possibility of generating spiral beams of different length when laser beams of different wavelengths illuminate a binary spiral axicon. Such beams can be used to manipulate micro- and nanoobjects. [ABSTRACT FROM AUTHOR]