Coherent perfect absorption and emisson of light in non-Hermitian and time-varying media

Abstract

In this talk, I will speak about our recent work on coherent perfect absorption (CPA) [1,2] and emission [3] of light in tailor-made resonators. I will highlight, in particular, the possibility to engineer spatial and spectral degeneracies for broadband absorption of arbitrary wavefrontsat an exceptional point as well as the topological aspects associated with perfect emission of thermal radiation. In the second part of my presentation, I will present new insights on the CPA effect in time-varying media, which can be well described by a pseudo-unitary Floquet scattering matrix [4]. [1] Y. Slobodkin, G. Weinberg, H. Hörner, K. Pichler, S. Rotter, and O. Katz, Science 377, 995 (2022) [2] H. Hörner, L. Wild, Y. Slobodkin, G. Weinberg, O. Katz, and S. Rotter, Phys. Rev. Lett. 133, 173801 (2024). [3] M. S. Ergoktas, A. Keçeba¸s, K. Despotelis, S. Soleymani, G. Bakan, A. Kocaba¸s, A. Principi, S. Rotter, ¸S. K. Özdemir, and C. Kocaba¸s, Science 384, 1122 (2024). [4] D. Globosits, J. Hüpfl, and S. Rotter, Phys. Rev. A 110, 053515 (2024).