Accession Number : AD1036364


Title :   Two Beam Energy Exchange in Hybrid Liquid Crystal Cells with Photorefractive Field Controlled Boundary Conditions (Postprint)


Descriptive Note : Journal Article


Corporate Author : University of Kyiv Kyiv Ukraine


Personal Author(s) : Reshetnyak,V Yu ; Pinkevych,I P ; Subota,S I ; Evans,D R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/1036364.pdf


Report Date : 12 Sep 2016


Pagination or Media Count : 11


Abstract : We develop a theory describing energy gain when two light beams intersect in a hybrid nematic liquid crystal (LC) cell with photorefractive crystalline substrates. A periodic space-charge field induced by interfering light beams in the photorefractive substrates penetrates into the LC layer and reorients the director. We account for two main mechanisms of the LC director reorientation: the interaction of the photorefractive field with the LC flexopolarization and the director easy axis at the cell boundaries. It is shown that the resulting director grating is a sum of two in-phase gratings: the flexoelectric effect driven grating and the boundary-driven grating. Each light beam diffracts from the induced gratings leading to an energy exchange between beams. We evaluate the signal beam gain coefficient and analyze its dependence on the director anchoring energy and the magnitude of the director easy axis modulation.


Descriptors :   liquid crystals , Diffraction , Dielectrics , Gratings(Spectra) , energy transfer , Photorefractive materials


Subject Categories : Non-electrical Energy Conversion
      Optics


Distribution Statement : APPROVED FOR PUBLIC RELEASE