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arXiv · 2103.03668

Towards a Broad-Band Coherent Perfect Absorption in systems without Scale-Invariance

Suwun Suwunnarat·Yaqian Tang·Mattis Reisner·Fabrice Mortessagne·Ulrich Kuhl·Tsampikos Kottos
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Abstract

We experimentally and theoretically challenge the concept of coherent perfect absorption (CPA) as a narrow frequency resonant mechanism associated with scattering processes that respect scale-invariance. Using a microwave platform, consisting of a lossy nonlinear resonator coupled to two interrogating antennas, we show that a coherent incident excitation can trigger a self-induced perfect absorption once its intensity exceeds a critical value. Importantly, a (near) perfect absorption persists for a broad band frequency range around the nonlinear CPA condition. Its origin is traced to a quartic behavior that the absorbance spectrum acquires in the proximity of a CPA associated with a new kind of exceptional point degeneracy related to the zeros of the nonlinear scattering operator.

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Suwun Suwunnarat, Yaqian Tang, Mattis Reisner, Fabrice Mortessagne, Ulrich Kuhl, Tsampikos Kottos. 2021-02-21. Towards a Broad-Band Coherent Perfect Absorption in systems without Scale-Invariance. https://doi.org/10.1038/s42005-021-00782-2

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