Phys.org November 2, 2023
Prominent non-Hermitian phenomena include coherent perfect absorption and its generalization, reflectionless scattering modes, in which electromagnetic scattering at the input ports is suppressed due to critical coupling with the power leaked to output ports, and interference phenomena. These concepts are ideally suited to enable real-time dynamic control over absorption, scattering and radiation. However, reflectionless scattering modes have not been observed in complex photonic platforms involving open systems and multiple inputs. An international team of researchers (USA – City University of New York, Germany) demonstrated the emergence of reflectionless scattering modes in a chaotic photonic microcavity involving over a thousand optical modes. They modelled the optical fields in a silicon stadium microcavity within a quasi-normal mode expansion, which captured a dense family of reflection zeros at the input ports, associated with reflectionless scattering modes. They observed non-Hermitian degeneracies of reflectionless scattering modes in the telecommunication wavelength band, enabling efficient dynamic control over light radiation from the cavity… read more. TECHNICAL ARTICLE
Experimental set-up and chaotic optical microresonator system. Credit: Nature Physics, Nov. 2, 2023Â