Editing Arbitrarily Linear Polarizations Using Programmable Metasurface

We propose a polarization-reprogrammable digital coding metasurface to realize arbitrarily linear polarization editing for reflected electromagnetic (EM) waves and beams. We present a digital coding element integrated with a PIN diode for switching the polarization conversion, which matches the digital 0 and 1 states. Based on the coding element, we combine the digital states and physical states of EM waves successfully. By arranging distinct coding sequences, we show that the polarization of the EM reflected beam can be controlled flexibly in real time. Not only are two orthogonally linear polarizations switched, but also arbitrary polarization directions can be achieved with specific coding sequences in a programmable manner. Such a manner can be accessibly used in communication and imaging applications. As a proof of concept, six different polarization states are presented to validate the proposed method. A metasurface sample with 30 x 30 elements is fabricated and measured in microwave frequency. The experimental results have good agreement with simulations and theoretical analyses. We envision that this work will promote the research of active polarization manipulation and extend its perspective from traditional physical fields to the information world.