Wavefront Shaping with a Tunable Metasurface: Creating Coldspots and Coherent Perfect Absorption at Arbitrary Frequencies

Abstract

Modern electronic systems operate in complex electromagnetic environments and must handle noise and unwanted coupling. The capability to isolate or reject unwanted signals for mitigating vulnerabilities is critical in any practical application. In this work, we describe the use of a binary programmable metasurface to (i) control the spatial degrees of freedom for waves propagating inside an electromagnetic cavity and demonstrate the ability to create nulls in the transmission coefficient between selected ports; and (ii) create the conditions for coherent perfect absorption. Both objectives are performed at arbitrary frequencies. In the first case a novel and effective optimization algorithm is presented that selectively generates coldspots over a single frequency band or simultaneously over multiple frequency bands. We show that this algorithm is successful with multiple input port configurations and varying optimization bandwidths. In the second case we establish how this technique can be used to establish a multi-port coherent perfect absorption state for the cavity.

References in corpus (10)

• Coherent Perfect Absorbers: Time-reversed Lasers
• Reference-less measurement of the transmission matrix of a highly scattering material using a DMD and phase retrieval techniques
• Programmable Metasurface-based RF Chain-free 8PSK Wireless Transmitter
• Universal Statistics of the Scattering Coefficient of Chaotic Microwave Cavities
• Statistics of Impedance and Scattering Matrices in Chaotic Microwave Cavities: Single Channel Case
• Statistics of Impedance and Scattering Matrices of Chaotic Microwave Cavities with Multiple Ports
• Spatio-temporal wavefront shaping in a microwave cavity
• Random Matrix Theory Approach to Chaotic Coherent Perfect Absorbers
• Experimental Examination of the Effect of Short Ray Trajectories in Two-port Wave-Chaotic Scattering Systems
• Missing level statistics and the power spectrum of level fluctuations analysis of three-dimensional chaotic microwave cavities

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