Spin angular momentum density and transverse energy flow of tightly focused kaleidoscope-structured vector optical fields

We propose a novel scheme for designing and generating kaleidoscope-structured vector optical fields (KS-VOFs) by analogy with the principle of multiple mirror reflection in a kaleidoscope. For KS-VOFs with symmetric polarization states, we show the symmetry properties of the focal fields with various shapes for different applications. The redistributing symmetric local spin angular momentum (SAM) density indicates that the design method of the KS-VOFs plays a role as a catalyst to the redistribution process of polarization states and local SAM conversion in the tight focusing process. Meanwhile, the controllable transverse energy flow in the focal plane can be used to transport multiple absorptive particles and then to be fixed at certain locations. Our results may find applications in optical machining, trapping, and manipulation.