Authors:
H. Gharagulyan
;
H. Grigoryan
;
M. S. Rafayelyan
;
A. H. Gevorgyan
and
R. B. Alaverdyan
Affiliation:
Yerevan State University, Armenia
Keyword(s):
Chiral Photonic Crystal, Cholesteric Liquid Crystal, Nonreciprocity, Selective Reflection, Inhomogeneous Pitch, Photonic Band Gap.
Related
Ontology
Subjects/Areas/Topics:
Photonic and Optoelectronic Materials and Devices
;
Photonics
;
Photonics, Optics and Laser Technology
Abstract:
In frame of this paper we have investigated reflection and transmission properties of light in chiral liquid-crystalline photonic structures with inhomogeneous pitch. We have experimentally confirmed and theoretically justified the existence of the phenomenon of nonreciprocity in the mentioned above systems. The liquid-crystalline cells through the contact of two and more cholesteric liquid crystals with different pitches and chiralities were prepared. The problem was solved by Berremann 4x4 matrix method. Our results can be used in optical diodes, transistors and logical elements, as well as for expansion of Bragg’s reflection range, namely in the systems as a broadband mirrors for circularly polarized light and in spatially tunable liquid-crystalline lasers with a pitch gradient.