Manipulating the variation of polarization during propagation along arbitrary circular trajectory of the Poincaré sphere

The spatial structure of polarization in the vector optical beam provides an additional degree of freedom to manipulate light and control the light–matter interaction. The manipulation of polarization in the propagation (longitudinal) direction opens new ways to enrich the vector optical beam, which also faces the problems of monotony at present. Here, we demonstrate an amplitude-phase-polarization joint modulation method to accurately control the variation of localized polarization during propagation, mapping arbitrary circular trajectory on the Poincaré sphere. In addition, a dual-mode vector optical beam has been generated, which realizes the cascading of independent variations of polarization in different longitudinal ranges.