Unlocking the Jones Matrix Full-parameter Regulation Via Bilayer Spatially Cascaded Metasurfaces

The linear modulation of electromagnetic (EM) waves can be fully represented by a Jones matrix, which is a $2\times 2$ matrix with eight manipulated parameters. Unlocking more free parameters means that meta-devices with more functionality can be realized. Many efforts have been devoted to unlocking more free parameters in the Jones matrix. However, unlocking the full-parameters is still a huge challenge. Here, we propose a scheme for unlocking the full-parameter of Jones matrices via the bilayer spatially cascaded birefringent metasurfaces. Moreover, a gradient descent-based inverse design algorithm is proposed to optimize the Jones matrix distribution of the bilayer metasurface. As a proof of concept, a Jones matrix eight-channel regulation meta-device is verified by simulation in the microwave region. The proposed strategy provides a new paradigm for the realization of multifunctional meta-devices.