New design of photonic band gap filter: the random dimer effect
Résumé
A new type of optical filter using photonic band gap materials is suggested. We consider photonic superlattices composed of two alternating photonic crystals. The structure is denoted as A/B/A/B……A/B, where photonic crystals A and B act as photonic wells and barriers, respectively. The propagation of electromagnetic waves in such one dimensional disordered photonic crystal is investigated by means the transfer matrix formalism. In particular the presence of short range correlation in disorder into the sample induces the suppression of localization. By introducing a short range intentionally binary disorder provides predicted resonance breaking down the Anderson localization. By properly adjusting the intrinsic dimer unit cell parameter i.e. dimer dielectric constants ?d, light can be transmitted over the whole sample with a very large localization length ? through a ballistic canal. Such findings open up possibilities in performing new design optical filter. Moreover with increasing the degree of disorder, by means the dimer concentration cd and the period number N, the quality in transmitting light around the resonance is significantly improved with the smoother corresponding allowed mini band.