Asymmetric energy transfer and optical diffraction in novel molecular glass with carbazole moiety

Abstract

Asymmetric energy transfer and optical diffraction under optically interfered beams was presented in composites with novel star-shaped molecular glass end-caped by carbazole moiety, α,α′,α″-tris-(4-(carbazoryl)-n-hexyloxyphenyl)-1,3,5-triisopropylbenzene (Tris). Composite consisted of Tris as host matrix, 2,4,7-trinitro-9-fluorenone (TNF) as a sensitizer, (S)-(-)-1-(4-nitrophenyl)-2-pyrrolidine-methanol (NPP) as a nonlinear optical dye and either tricresyl phosphate (TCP), n-butyl benzyl phthalate (BBP), diphenyl phthalate (DPP), or dicyclohexyl phthalate (DCP) as a plasticizer. Asymmetric two beam coupling (asymmetric energy transfer) and beam diffraction were achieved with no external field. Glass transition temperature of the composites plays an important role for these phenomena of asymmetric energy transfer and optical diffraction with no external field. Highest net gain coefficient of 59.7 cm−1 with optical gain of 151.3 cm−1 and absorption coefficient of 91.6 cm−1 was obtained for Tris/NPP/DPP/TNF (35/20/40/5) composite. TNF anion produced by laser illumination plays a key role of beam diffraction and asymmetric two beam coupling in the composites.