All-optical routing control based on coherently induced high reflection band and high transmission band in a medium of cold atoms
Jin‐Hui Wu
Abstract
On the basis of coherently induced photonic gap structures,a new all-optical routing control scheme is proposed to simultaneously control the propagation dynamics of two weak light signals.With the transfer-matrix method to describe the coherent scattering of light waves in periodic media and the density-matrix equations to describe the resonant interaction between monochromatic laser fields and multi-level atoms,the steady reflection and transmission spectra are calculated for a coherently driven ultra-cold atomic ensemble as the control medium.The results show that,by changing the spatial patterns,intensity,and frequencies of two strong laser fields,a pair of special frequency bands(with ~95% reflectivity or ~95% transmissivity) can be first established near the probe resonance and then be manipulated at any time to induce two weak light signals of different frequencies into the desired network channels.This scheme well satisfies the basic requirements of low-deformation and low-loss for all-optical routing control of weak light signals in the field of quantum information processing.