Analysis of atomic density distributions in optical lattices using an optical mask

We use an optical-mask technique to study the atomic density distribution in two types of optical lattices. In a two-beam lattice involving magnetic-field-induced laser cooling (MILC lattice), the measurements show, in agreement with simulations, an atomic distribution having periodicity equal to half the wavelength, λ, of the lattice fields and a modulation depth of about 20%. In a four-beam optical lattice involving Raman transitions, clear evidence of a λ/4-periodicity of the atomic distribution is found.