Perfect Absorption by an Atomically Thin Crystal
Jason Horng, Eric W. Martin, Yu-Hsun Chou, Emmanuel Courtade, Tsu-chi Chang, Chu-Yuan Hsu, Michael-Henr Wentzel, Hanna G. Ruth, Tien-chang Lu, Steven T. Cundiff, Feng Wang, Hui Deng
Abstract
Perfect absorption by a two-dimensional (2D) system allows extreme sensitivity to small modulations in light intensity, enabling a host of applications. The phenomenon typically requires complex photonic structures or multiple coherent beams, but this study demonstrates perfect absorption using just a monolayer of MoSe${}_{2}$ in front of a flat mirror. Success is due to the strong exciton-photon interaction (compared to loss and inhomogeneity) that is unique to 2D semiconductors. With its robustness, simplicity, and flexibility in exciton control, this system provides a route for ultrafast energy-efficient modulation of perfect absorption on integrated semiconductor platforms.