Three-dimensional modulations on the states of polarization of light fields

Light fields with spatially structured states of polarization (SoPs) are gathering increasing attention because of their potential applications from optical imaging and micromanipulation to classical and quantum communications. Meanwhile, the concepts within structured light fields have been extended and applied to acoustic, electron, and matter waves. In this article, we review recent developments of the SoP modulation of light fields, especially focusing on three-dimensional (3D) modulations on the SoPs of light fields. The recent progress and novel implementations based on 3D spin-dependent separation are discussed. Following the discussions to this physical phenomenon, we then describe recent developments on the vector fields with 3D structured SoP and intensity distributions, namely, 3D vector fields. The discussed phenomena inspire us to explore other structured light fields for the expansion of applications in biomedical, information science, quantum optics, and so on.