Abstract:
This thesis describes the photonic properties of a one-dimensional, periodically-ordered atomic vapour of rubidium. Building on previous experiments, we have developed and set up a completely new experimental system. Three experiments were performed.
In the first part we probe an ordered atomic cloud with a weak probe-beam whose angle of incidence is only 2 degrees. Because of a good overlap between the probe beam and the atomic cloud, and due to multiple scattering regimes, we reached a high Bragg-reflectivity of 80% and proved the existence of a photonic band gap in 1-D systems.
In order to minimize the losses we investigate our system in the vicinity of the atomic resonance with electromagnetically-induced transparency. A new band gap was discovered and characterized. Furthermore, we present a possible application as an all optical switch.
In the last part we pump our system with near resonant light and achieve gain. We investigate two possible amplification mechanisms (Raman-gain and four-wave mixing). As a result of the interplay between a positive feedback (multiple Bragg-reflection) and gain (FWM) we demonstrate the first laser consisting only of cold atoms.