On the stability of optical lattices
  In this article, we present an analysis of the stability of optical lattices. Starting with the study of an unstable optical lattice, we establish a necessary and sufficient condition for intrinsic phase stability, and discuss two practical solutions to fulfill this condition, namely minimal and folded optical lattices. We then present a particular example of two-dimensional folded optical lattice which has the advantage of being symmetric, power recycling and having a convenient geometry. We have used this lattice for laser collimation of a continuous cesium beam in a fountain geometry. 
G. Di Domenico, N. Castagna, M.D. Plimmer, P. Thomann, A.V.   Taichenachev, V.I. Yudin