In this thesis the Collective Atomic Recoil Laser (CARL) model of Bonifacio et al., which described CARL by twolevel atoms, is extended to describe threelevel atoms with ladder and ᴧ energy level configurations. It is shown that, in contrast to the case of twolevel atoms where the CARL instability is quenched at high pump rates with significant atomic excitation, CARL instabilities involving 3level atoms can persist at high pump rates due to transitions between the populated states being dipole forbidden. It is also demonstrated for the ladder configuration that, when the system is operated in the twophoton superfluorescent regime,introduction of centre of mass motion and atomic bunching result in symmetry breaking in the sign of detuning from fieldatom resonance. CARL instabilities involving threelevel atoms with ᴧ energy level configurations are investigated for two distinct cases : in the first the two ground states are degenerate, whereas in the second the ground states are nondegenerate. It is demonstrated that in the degenerate case, it is possible to decouple the atomic centre of mass motion from the internal atomic degrees of freedom. It is also demonstrated that for the nondegenerate case it is possible for the the atomic motion to be decoupled from the atomic coherence but not the atomic population. The population difference remains constant throughout the interaction, so the population inversion acts as a parameter in the equation for the force experienced by the atoms. Consequently,for both the degenerate and nondegenerate ᴧ configurations, CARL instabilities can occur at higher pump intensities than for the case of twolevel atoms.
Date of Award  19 Sep 2016 

Original language  English 

Awarding Institution   University Of Strathclyde


Sponsors  University of Strathclyde & EPSRC (Engineering and Physical Sciences Research Council) 

Supervisor  Gordon Robb (Supervisor) & Aidan Arnold (Supervisor) 
