  Light transport in a dilute photonic crystal is considered. The analytical
expression for the transmission coefficient is derived.Straightening of light
under certain conditions in a one-dimensional photonic crystal is predicted.
Such behavior is caused by the formation of a localized state in transversal
motion. The main contribution to the central diffracted wave transmission
coefficient is due to states, that either close to the conductance bands bottom
or deeply localized in the forbidden gap. Both these states suppress mobility
in the transverse direction and force light to be straightened. Straightening
of light in the optical region along with small reflection make these systems
very promising for use in solar cells.
