Journal of Modern Optics
Group velocity control of a light pulse using giant nonlinearities
Z. C. Zhuo, Byoung Seung HAM, J. B. Kim, Xue Mei Su
Abstract
In this paper, we propose and demonstrate a scheme to enhance nonlinearities of a probe pulse at both cross-phase modulation (XPM) and self-phase modulation (SPM) in a four-level system. Based on standing wave grating generated by counter-propagating resonant signal fields and an additional off-resonant coupling field, a giant nonlinear refractive index of the resonant probe field is obtained with absorption suppressed. Group velocity of the probe pulse can be controlled by both XPM and SPM nonlinearities.