Controlling Stochastic Electromagnetic Process by Dynamically Random Coding Metasurface

Abstract Random signals are pervasive and play a crucial role in both information science and technology. Traditionally, research on random signals has been concentrated on the circuit domain, focusing on aspects like random signal generation and filtering techniques. However, the random electromagnetic field in the wave domain lacks effective methods to manipulate it, though it is a prevalent form of random signal that permeates the cosmic background. Here, the proposal is to generate and directly manipulate random electromagnetic signals (RES) by presenting a dynamically random coding metasurface (DRCM). For this target, a probabilistic framework to analyze DRCM and uncover principles to control the RES process is developed. In specific, three techniques for RES manipulations, including code mutation, inheritance, and shift operations, to generate the desired RES properties are proposed. The experimental results validate these theoretical concepts. This work establishes a theoretical foundation for studying the metasurfaces within the probability domain and offers fundamental methods for achieving RES manipulation. Besides generating RES, the proposed coding metasurface can also implement many other functionalities because of its reprogrammable nature, and hence it can be readily applied to practical applications in wireless communication, cryptography, and radar technology.