Polarization Generation and Manipulation Based on Nonlinear Plasmonic Metasurfaces

Polarization is one of the most important properties of light, which is also a typical dimension for light field manipulation. With specially designed meta-atoms and tailorable phase distribution, metasurfaces have been employed to achieve arbitrary polarization state in linear regime. Moreover, metasurface is also a platform for various types of nonlinear light generation, which can be used to realize an integrated polarized light source combined with its powerful capability of polarization manipulation. Here, a nonlinear plasmonic metasurface that is able to simultaneously realize nonlinear light generation and polarization manipulation is demonstrated. Two separated second harmonic (SH) beams with orthogonal circular polarizations are achieved from a linearly polarized fundamental wave (FW), and illuminated by circularly polarized FW the same nonlinear plasmonic metasurface can generate linearly polarized SH, which can be viewed as an SH quarter-wave plate. Furthermore, arbitrary elliptical polarized SH can also be obtained from properly designed nonlinear metasurfaces. This design provides a new approach for miniaturized light source for special polarization requirement, which may have potential applications in integrated optics.