Figure 1

(a) Schematic representation of the EIG scheme. Atomic ensemble consisting of \(\Lambda \)-level atoms is excited by a weak TW probe field and simultaneously coupled by strong SW and LG fields. Due to the phase and amplitude modulations exerted by the coupling fields, the incident probe field is diffracted into high-order diffraction after propagating through such an ensemble. (b) Atomic energy levels scheme. Other details are given in the text. The figure was prepared using Microsoft PowerPoint, Microsoft Office Professional Plus 2016, www.microsoft.com.