2013/11/27 by Bakht Amin Bacha, Bacha, Bakht Amin, Fazal Ghafoor +1
Physics and Astronomy · #Quantum optics and atomic interactions #Laser-Matter Interactions and Applications #Photorefractive and Nonlinear Optics
paper · pdf · doi:10.48550/arxiv.1311.6896
We investigate nonlinear Kerr-induced coherence effect on a superluminal probing light pulse in a gain-assisted N-type 4-level atomic system via an intense monochromatic laser field. The dispersion exhibits a novel, interesting and useful two-paired double gain lines processes. The system displays lossless characteristics similar to [L. J. Wang, A. Kuzmich, A. Dogariu, Nature 406, 277 (2000)] but with advantages of multiple controllable anomalous regions, significantly enhanced superluminal behavior and relaxed temperature, states of matter regardless of its isotropic or anisotropic conditions. Unlike the instability in [A. M. Akulshin, S. Barreiro, and A. Lezama, Phys. Rev. Lett. 82, 4277 (1999)], the present system also overcomes the instable-limit by the Kerr-induced coherence effect in the system. Indeed, the coherence enhances the group velocity remarkably by at least -30 ms more than of an instable Kerr-free system with almost negligible distortion in the retrieved pulse.