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Updated: Aug 31, 2025

Simulation, Fabrication and Characterization of THz Metamaterial Absorbers
Published on: December 27, 2012
Massively degenerate coherent perfect absorber for arbitrary wavefronts
Yevgeny Slobodkin1, Gil Weinberg1, Helmut Hörner2
1Applied Physics Department, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
Abstract:
One of the key insights of non-Hermitian photonics is that well-established concepts such as the laser can be operated in reverse to realize a coherent perfect absorber (CPA). Although conceptually appealing, such CPAs are limited so far to a single, judiciously shaped wavefront or mode. Here, we demonstrate how this limitation can be overcome by time-reversing a degenerate cavity laser based on a unique cavity that self-images any incident light field onto itself. Placing a weak, critically coupled absorber into this cavity, any incoming wavefront, even a complex and dynamically varying speckle pattern, is absorbed with close to perfect efficiency in a massively parallel interference process. These characteristics open up interesting new possibilities for applications in light harvesting, energy delivery, light control, and imaging.
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