Optics Express
Three-color reflections in one-dimensional ordered and disordered atomic lattices with trapped N-type cold atoms
Maohua Wang, Tianming Li, Yan Zhang, Xiaoshan Pei, Hong Wei Yang
Abstract
Investigating and controlling light propagation in one-dimensional (1D) ordered and disordered atomic lattices is critical both fundamentally and for applications. In this study, cold atoms are trapped in 1D optical lattice and driven to the four-level N configuration. In each period, the atoms exhibit a Gaussian density distribution with the average atomic density N 0 (1 + Δ k ). When the random number Δ k = 0 (the atomic density N k ( z )) corresponding to an ordered 1D atomic lattice, there are three reflection regions of high reflectivity located in two EIT windows and one large detuning range. However, the atomic density may increase ( N k + ( z ) with Δ k > 0) or decrease ( N k − ( z ) with Δ k < 0) owing to the imperfect manufacturing process or random distribution of atoms corresponding to a disordered atomic lattice. The results show that the width and height of reflections can be raised (reduced) by the increased (decreased) ratio of N k + ( z ) / N k ( z ) ( N k − ( z ) / N k ( z ) ) with the random distribution of lattice cells with N k + ( z ) ( N k − ( z ) ). When a cluster of disordered lattice cells with N k + ( z ) and N k − ( z )