Tunneling induced broadband absorber based on coupled quantum dots
Yandong Peng, Aihong Yang, Bing Chen +3 more
Abstract A tunable broadband absorber induced by resonant tunneling is investigated in a coupled quantum-dot (CQD) system. The CQDs show a narrow absorption in a linear case. When the inter-dot tunneling arises, constructive interference occurs in a nonlinear absorption, which exhibits a large absorption in a wide frequency range. Therefore, the total absorption spectrum is much more broadened, and its bandwidth under given conditions can be one order of magnitude larger than that of the liner absorption. Bright-state coherence is employed to qualitatively explain the numerical results. Furthermore, the dependence of the broad absorption on the tunneling strength and analytical expression of the nonlinear absorption spectrum are also provided.
Journal of Optics•Jun 20, 2017•3 citations