Ordered periodic microporous and mesoporous materials allow the construction of composites with many guest types, e.g. organic molecules, inorganic ions, semiconductor clusters or polymers. These guest/host materials combine high stability of the inorganic host system, new structure forming mechanisms due to the confinement of guests in well defined pores, and a modular composition. This could lend to new optical materials which are described in this paper by examples in switches, nonlinear optics and lasers.