Slow light in molecular-aggregate nanofilms.

We study slow-light performance of molecular aggregates arranged in nanofilms by means of coherent population oscillations. The molecular cooperative behavior inside the aggregate enhances the delay of input signals in the gigahertz range in comparison with other coherent population oscillation-based devices. Moreover, the problem of residual absorption present in coherent population oscillation processes is removed. We also propose an optical switch between different delays by exploiting the optical bistability of these aggregates.