Dressing field control of band gap reflection is investigated in an inverse Y-type four-level atomic system. It is shown that when the dressing field is blocked, a band gap reflection with a maximum bandwidth and nearly ~90% reflectivity can be achieved for the detuning of the coupling field . When a weak dressing field is applied to the system (the intensity is much less than that of the coupling field), a narrowing top flat with ~86% reflectivity of the band gap reflection is observed in comparison with that in the first case. We also show that the band gap reflection can be dramatically suppressed due to the collapse of the stop band when a strong dressing field (the intensity is comparable with or larger than that of the coupling field) is employed. This control of photonic band gap reflection can be used in the applications of all-optical reflection mirrors and band optical filters.
Few-Photon All-Optical Modulation in a Photonic Band-Gap Fiber
