Dynamics of atoms in a lattice of ring traps

Realization of a new type of optical lattice made of a 1D stack of ring traps is presented. This optical lattice results from the interference of a Gaussian beam with a backward hollow beam. The latter is realized through an optical system including essentially two conical lenses, leading to an annular beam with a constant phase in the transverse plane, contrary to e.g. a Laguerre Gaussian beam. It results from the interference process a series of dark rings, with a periodicity of λ/2 along the z-axis, a diameter of 200 m and a thickness of 10 m.