We experimentally study the generation and storage of double slow light pulses in a Pr～(3+):Y_2 SiO_5 crystal.Under electromagnetically induced transparency,a single signal pulse is stored in the spin coherence of the crystal.By simultaneously switching on two control fields to recall the stored information,the spin coherence is converted into two slow light pulses with distinct frequencies.Furthermore,the storage and controlled retrieval of double slow light pulses are obtained by manipulating the control fields.This study of double slow light pulses may have practical applications in information processing and all-optical networks.
Through the picture of dressed states,this paper investigates the spontaneous emission spectrum from a microwavedriven three-level atom embedded in double-band photonic crystals.The physical dynamics of the phase dependent phenomenon are analysed by comparing two models 'upper level coupling' and 'lower level coupling'.When the phase is changed from 0 to π,the variety of spontaneous emission spectra from either of the two models are inverse to each other,in which the relative height and width of the peaks are determined by the density of states in photonic crystals.
We investigate the resonance fluorescence spectrum of an atomic three-level ladder system driven by two laser fields.We show that such a system emulates to a large degree a V-type atom with parallel dipole moments-the latter being a system that exhibits spontaneously generated coherence and can display ultrasharp spectral lines.We find a suitable energy scheme in a 85Rb atom and experimentally observe the narrowing of the central peak in a rubidium atomic beam.The corresponding spectrum can convincingly demonstrate the existence of spontaneously generated coherence.
