Effect of atomic coherence on temporal cloaking in atomic vapors

We discuss a different scheme to achieve temporal cloaking in warm atomic vapors. Instead of creating a temporal-spatial window in a patched broadband short optical pulse using static differential dispersion of an optical fiber, we create a temporal-spatial window by directly controlling the propagation velocities of a pair of correlated narrow-band long optical pulses. This method eliminates the phase noise introduced by the broadband short-pulse swapping technique. When the event medium has a fast relaxation rate this leads to a temporal-cloaking scheme similar to that reported in fibers. When the event-medium relaxation cannot be neglected, we discuss a matched-mode scheme that can eliminate the phase change caused by the event field. The advantages of the dynamically and actively controlled atomic system over previously reported work are discussed.