VSCPT subrecoil laser cooling of atoms with a non-degenerated (J=0) ground state

We present new investigations on a five-level laser cooling scheme which can be used for subrecoil cooling of the group of even-even isotopes. System dynamics and the temporal evolution of the atomic momentum distribution are examined numerically in the case of ²⁰⁰Hg. We prove important features, e.g. constant efficiency at long interaction times as well as the influence of relaxation of coherences on the cooling process.     

Phase correlation of laser waves with arbitrary frequency spacing

The theoretically predicted correlation of laser phase fluctuations in Lambda-type interaction schemes is experimentally demonstrated. We show that the mechanism of correlation in a Lambda scheme is restricted to high-frequency noise components, whereas in a double-Lambda scheme, due to the laser phase locking in a closed-loop interaction, it extends to all noise frequencies. In this case the correlation is weakly sensitive to coherence losses. Thus the double-Lambda scheme can be used to correlate electromagnetic fields with carrier frequency differences beyond the GHz regime.     

Generation and intrinsic dynamics of ring dark solitary waves

 We present experimental results on the evolution of ring dark solitary waves generated by computer-synthesized holograms. The data obtained and the detailed comparative numerical simulations show that this approach ensures reproduction of the correct intensity and phase portrait of the dark wave at the entrance of the nonlinear medium. The transverse dynamics at both even and odd initial conditions is studied and compared with the theory and simulations. Received: 24 June 1996