Nonlinear optics of periodic and quasiperiodic structure

Periodic and quasiperiodic structures are known to possess some very special properties. Recent technological breakthrough in poling techniques in nonlinear materials has rendered nonlinear variants of such structures realizable. We review some of the latest developments in nonlinear optics of these systems. We show that the use of such structures leads to several major advantages like lowering of threshold, increase in efficiency of nonlinear mixing, fabrication of media with better characteristics, etc.