Abstract
When the interactions of the two coupling transitions from an excited level to two nearly degenerate ground levels with the same vacuum occur in a four-level tripod-scheme atomic system, vacuum-induced coherence (VIC) results from the quantum interference between the two spontaneous transitions. We investigate the effects of VIC and the relative phase between the two coupling fields on the probe absorption and dispersion properties as well as the group velocity of the probe field. We find that by adjusting the incoherent pumping field and VIC as well as the relative phase, the central absorption peak in the double transparency spectrum reduces, even develops into a gain dip, and the probe field propagates at a velocity from superluminal to subluminal. It is particularly pointed out that the subluminal light propagation with gain without inversion can be realized in such a system. The physical interpretation of the phenomena has been given.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Physics B: Atomic, Molecular and Optical Physics
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
