Automatic transformation of polarization state of light in void medium

Abstract

Abstract Customized polarization state of light plays a pivotal role in numerous scientific domains. Under normal circumstances, light always maintains its polarization state during transmission in void medium or the free space. However, in this work, we have observed that the polarization state of a light beam can be automatically transformed during the propagation without involving a waveplate or scattering of air. The beam changes polarization states at different distances in the free space propagation. Moreover, while polarization states can be preset at different distances, the intensity and phase of the light beam can also be independently designed. The mechanism behind this phenomenon is due to the superposition and diffraction of the controlled light beams. The phenomenon paves the way for applications of constructing key devices, e.g. optical isolator, and offers a broader range of possibilities for applications such as tunable structured devices, optical diodes, and so on.