Coherent atomic mirror formed by randomly distributed ions inside a crystal.

Abstract

Spatial distribution of atoms plays an important role in the interaction of atomic ensembles and electromagnetic fields. In this Letter, we show that by spatio-spectral tailoring of atomic absorption, one can effectively carve out a periodic array from randomly distributed atomic ensembles hosted by a solid-state crystal. Furthermore, we observe collective atomic resonances and coherent backscattering of light from rare-earth-doped crystals. Coherent backscattering as high as 20% was observed for light at telecom wavelength from Er ions, forming an effective array with over 5000 centers.