Experimental synthesis of vector-twisted beams with controllable higher-order Poincaré polarization states

We propose a protocol for efficient synthesis of vector-twisted beams with higher-order Poincaré polarization states via the random vector-mode decomposition method, where the polarization state and twist phase information are encoded into the deterministic and random complex amplitude parts of vector modes, respectively. Further, a compact vector-twisted beam generation system involving a phase-only spatial light modulator and a common-path interferometer is established. Multiple types of vector-twisted beams are successfully synthesized, and their propagation properties, including intensity, polarization state, and degree of polarization, are investigated in detail. Our results reveal that the twist phase can induce the local spin angular momentum splitting or redistribution and resist the coherence-induced depolarization during beam propagation, offering what we believe to be a new degree of freedom to modulate polarization in random vector beams.