Generation and manipulation of multi-twisted beams via azimuthal shift factors

Abstract

We develop the effective experimental approach to generate multi-twisted beams (MTBs) with twisted intensity lobes by superimposing helical phases consisting of multiple independent sub-phases with different azimuthal shift factors. The MTBs' energy flows and propagation properties are also investigated, indicating that such beams exhibit twisted properties. The azimuthal shift factor determines the twisted intensity distributions, and the number of twisted lobes depends on the sub-phase number. The bright lobes of a MTB possess the shapes of thin spiral lines, and the intensity pattern depends on the topological charge. Diverse MTBs can be generated by flexibly manipulating the azimuthal shift factors and the sub-phase number. Also, various mirror-symmetrical twisted beams are constructed using the matrix flip scheme, further enriching the light structures of MTBs. Numerical simulation and experimental results are consistent. Furthermore, the capture and guide of microspheres via the MTBs are experimentally executed and demonstrate the feasibility and practicability of our generated MTBs. The various MTBs will likely give rise to potential applications in fabricating chiral nanostructures and manipulating microparticles.