Fast compression of a cold atomic cloud using a blue detuned crossed   dipole trap
  We present the experimental realization of a compressible blue detuned crossed dipole trap for cold atoms allowing for fast dynamical compression (~ 5 - 10 ms) of 5x10^7 Rubidium atoms up to densities of ~ 10^13 cm^-3. The dipole trap consists of two intersecting tubes of blue-detuned laser light. These tubes are formed using a single, rapidly rotating laser beam which, for sufficiently fast rotation frequencies, can be accurately described by a quasi-static potential. The atomic cloud is compressed by dynamically reducing the trap volume leading to densities close to the Ioffe-Reggel criterion for light localization. 
Tom Bienaime, Giovanni Barontini, Laure Mercier de Lepinay, Louis   Bellando, Julien Chabe, Robin Kaiser
physics.atom-ph cond-mat.quant-gas