We study the photonic properties of a one-dimensional periodic macroscopic ensemble of cold atoms. A large number of atoms is trapped in a 1D optical lattice, thus forming layers of disordered atomic pancakes. This induces a periodic modulation of the refractive index, which can yield a large Bragg reflection [1]. In the past, adding four-wave mixing or EIT allowed us to obtain mirrorless optical parametric oscillation [2] and a two-port all-optical switch [3].
I will summarize these past results, which are all steady-state experiments. Now, we are studying temporal dynamical effects, in particular the optical transients in the Bragg reflection. I will show preliminary data on the existence of a small "flash" effect [4] in the Bragg reflection at the switch-off of the incident beam, and on the superradiant rate of the decay.
Finally, I will briefly discuss research prospects on this system: pulse propagation (slow light, quantum memory), spontaneous emission in the band gap, nonlinear effects, etc.
[1] A. Schilke, C. Zimmermann, P. W. Courteille, W. Guerin, Phys. Rev. Lett. 106, 223903 (2011).
[2] A. Schilke, C. Zimmermann, P. W. Courteille, W. Guerin, Nature Phot. 6, 101 (2012).
[3] A. Schilke, C. Zimmermann, W. Guerin, Phys. Rev. A 86, 023809 (2012).
[4] C. C. Kwong et al., Phys. Rev. Lett. 113, 223601 (2014).