All-optical control of the speed of light in molecular-aggregate nanofilms: effects of the two-exciton dynamics

G. Martínez-Calzada, E. Díaz, E. Cabrera-Granado and O. G. Calderón
(Universidad Complutense de Madrid, E-28040-Madrid, Spain)

We study the behavior of an optical pulse within a nanometric film of linear molecular aggregates. Generalizing previous reports [1] we have considered the formation and annihilation of two excitons by means of a four-level model [2, 3]. Our numerical simulations show that the two-exciton dynamics plays a significant role and still supports remarkable fractional delays of the pulses in comparison with other non-nanometric systems. More importantly the pulse distortion and the signal gain remain within relevant limits for technological applications [4]. Our work is focused on analyzing the best set of parameters that give rise to an optimal response, as well as the effects of disorder on the performance of the system. We conclude that slow light processes are a robust phenomenon in these systems when the complexity of the exciton dynamics is increased.

[1] E. Cabrera-Granado, E. Díaz and O. G. Calderón, Physical Review Letters, 107, 013901 (2011).
[2] H. Glaeske, V. A. Malyshev and K. H. Feller, Journal of Chemical Physics, 114, 1966 (2001).
[3] J. A. Klugkist, V. A. Malyshev and J. Knoester, Journal of Chemical Physics, 128, 084706 (2008).
[4] G. Martínez-Calzada, Master Thesis, Universidad Complutense de Madrid [to be published] (2015).