Superluminal Vector Solitons In Multiple Level Atomic System

Soliton produced in an atomic medium is one of hot topics in the area of quantum optics and nonlinear optics in recent years. As superluminal propagation was proposed, optical solitons with a superluminal group velocity have attracted great interest. In active-Raman-gain system, the Kerr nonlinearity was largely enhanced, while the gains of probes fields are almost vanishing. Optical solitons that propagated with a superluminal group velocity in an active-Raman-gain scheme were investigated.We investigate generation of superluminal temporal vector optical solitons in a five-level M-type atomic system and a seven-level3(?)-type system within active-Raman-gain regime. By analyzing the linear and nonlinear optical properties of the system, we find that the dispersion effects of the probe fields can be well balanced by self-phase and cross-phase modulation of the Kerr nonlinearity, which leads to the formation of optical vector solitons with superluminal propagating group velocity. By choosing proper parameters, a various of temporal vector solitons can form in these systems. Moreover, Manakov temporal vector solitons can also be realized.Our work on superluminal vector solitons based on the ARG schemes may have potential applications in some related areas such as rapidly responding optical device, quantum phase gate and fast light storage.