TY - CHAP A1 - Grytsenko, Kostyantyn A1 - Slominskii, Yu L. A1 - Tolmachev, O. I. A1 - Resel, R. A1 - Ksensov, S. A1 - Schrader, Sigurd T1 - Enigma of the second harmonic generation in oriented film of symmetric squaraine N2 - Second harmonic generation (SHG) in the oriented film of symmetric squaraine (Sq) was studied. Oriented Sq film on aligned polytetrafluoroethylyne (PTFE) sublayer prepared by vacuum deposition with subsequent rubbing using a cloth has been obtained. However, the mechanisms of orientation and SHG are still not clear. Methyl and ethyl substituted hydroxyl-Sq (OHSq) compounds formed oriented films with dichroic ratio of 8 on PTFE layer but with dichroic ratio of 1,5 on Teflon AF. Second layer deposition of Me-OHSq on Et-OHSq or of Et-OHSq on Me-OHSq led to an increase of the film dichroic ratio. Only the film, where Me-OHSq was first layer, exhibits an increase of SHG signal after deposition of second layer. Small differences in bi-layered OHSq films structure was detected by X-Ray diffraction (XRD) spectra. KW - dye KW - solid KW - film KW - squaraine KW - optical spectra KW - deposition KW - second harmonic generation Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15183 SP - 324 EP - 331 PB - Society of Photo-Optical Instrumentation Engineers (SPIE) ER -