INTERFERENCE OF MODE-INSTABILITIES AND PATTERN-FORMATION IN ANHARMONIC LATTICES

On an example of optically excited Klein-Gordon lattice, a striking ne w feature of anharmonic lattices related to dynamical coherent structu re (pattern) formation is reported. It is shown that two factors are i mportant for pattern formation: (i) lattice discreteness, which strong ly reduces the number of lattice spatial modes among which the energy of external field is shared, and (ii) destructive interference of modu lation instabilities of these modes resulting in stability of the patt ern. Possible experimental realization is discussed.