Broad omnidirectional high-precision two-channel filter design using genetic algorithm

An application of the genetic algorithm in designing omnidirectional optical filters is reported in this paper. Concerning different periodic numbers and thickness ratios in the photonic crystal, we gave some optimization examples and finally achieved a photonic heterostructure with very broad omnidirectional filter bandwidth as well as two very narrow transmission windows. And they are found that when the normal incident beam is tilted at a negligibly small angle, the perfect transmittance peak will vanish. Hence, this heterostructure can be regarded as an omnidirectional high-precision two-channel filters with potential application in optical filters, optical switches, and many other optical telecommunication areas.