Full polarization states modulating via an ultra-thin quarter-wave plate

We theoretically and numerically demonstrate a design of an ultra-thin quarter-wave plate (QWP) based on plasmonic metasurface. With the designed QWP, the ellipticity of the output light can be generalized as X = 2sin(theta )cos(theta), providing a convenient way to calculate the polarization states of the output light. With such a strategy, output lights with any desired polarization states including linear, circular and especially elliptical can be obtained by adjusting the incident polarization angle theta. The Jones vector is adopted to theoretically explore the underlying physics of polarization conversion. Moreover, the finite-difference time-domain (FDTD) simulations are utilized to verify the theoretical results. These results will deepen our understanding of polarization conversion and provide helpful guidelines in designing ultra-thin polarization-dependent devices.