Twist defect in chiral photonic structures.
We demonstrate that twisting one part of a chiral photonic structure about its helical axis produces a single circularly polarized localized mode that gives rise to an anomalous crossover in propagation. Up to a crossover thickness, this defect results in a peak in transmission and exponential scaling of the linewidth for a circularly polarized wave with the same handedness as structure. Above the crossover, however, the linewidth saturates and the defect mode can be excited only by the oppositely polarized wave, resulting in a peak in reflection instead of transmission.
Kopp
Victor I
VI
Chiral Photonics, Inc., Clifton, New Jersey 07012 and Department of Physics, Queens College of CUNY, Flushing, New York 11367, USA.
Genack
Azriel Z
AZ