Chinese Optics Letters
Bragg reflection in a quantum periodic structure
Yue-Yue Chen, Xunli Feng Xunli Feng, Zhizhan Xu, and Chengpu Liu and Chengpu Liu
Abstract
We investigate the reflected field for few-cycle ultra-short laser pulses propagating through resonant media embedded within wavelength-scale structures.Full-wave Maxwell-Bloch equations are solved numerically by using the finite-difference time-domain method.The results show that the spectral feature of the reflected spectrum is determined by the Bragg reflection condition, and that the periodic structure of a dense atomic system can be regarded as a one-dimensional photonic crystal and even as a highly reflective multilayer film.Our study explains the suppression of the frequency shifts in the reflected spectrum based on the Bragg reflection theory and provides a method to control the frequency and frequency intervals of the spectral spikes in the reflected spectrum.