Optical propagation properties in a quantum dot-DNA coupling system

We theoretically investigate the slow- and fast-light phenomena caused by the coupling between peptide quantum dot (QD) and DNA molecules with the presence of strong pump light and weak signal light simultaneously. In this QD-DNA system, significant changes of the velocity of signal light can be observed when pump-exciton detuning and signal-exciton detuning are adjusted properly. Slow and fast signal light with little absorption can be obtained by adjusting the pump intensity when the pump field is off-resonant. It can be shown clearly that these phenomena cannot occur without the QD-DNA coupling. The scheme proposed here will lead people to know more about the optical behaviors of the QD-DNA system with the currently popular pump-probe technique. (c) 2012 Optical Society of America