Ultraefficient and Port-Selective Wireless Power Transfer in Complex Wave Environment via Coherent Perfect Absorption

초록

Controlling where electromagnetic energy is ultimately absorbed is more challenging than controlling where it is focused, and this challenge is especially critical for wireless power transfer (WPT) in complex environments. Conventional beamforming and time-reversal (TR) approaches can achieve spatial focusing in such settings but suffer from low transfer efficiency, as energy is largely reradiated or redistributed after focusing. Coherent perfect absorption (CPA) offers a fundamentally different approach by enforcing complete absorption through engineered interference. However, prior experimental demonstrations have been limited to single-loss channel scenarios, preventing selective power delivery in realistic environments where multiple loss channels exist. Here, we introduce an ultraefficient, port-selective CPA-based WPT scheme in complex wave environments, which we experimentally demonstrate using a quasi-2-D wave-chaotic cavity. By employing rectifiers with distinct operating frequency characteristics, we deliberately break the degeneracy among competing loss channels, thereby establishing an effective single-loss channel CPA condition within an otherwise multiloss channel environment. As a result, CPA can be enforced selectively at a chosen rectifier port. Under each CPA condition, near-perfect absorption is achieved at the intended rectifier port, enabling position and thus frequency-selective WPT with high end-to-end efficiency.

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