Dynamics of the photoexictation of azo dye-doped liquid crystals probing by pumped attenuated total reflection

Kuang-Yao Lo, Chia Yi Huang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


Kinetics of the photoexcitation of azo-dye doped liquid crystals (ADDLCs) is observed by the improved attenuated total reflection leading a pump light into a coupling prism, namely pumped ATR (PATR) experiment. The technique of ATR could be applied on an LC cell based on that the guide mode is overcome by the usage of an isotropic surface, which is also a usual way to observe the reaction involving the adsorption effect. The evanescent wave of the pump light induces the photoexcitation of azo dye at the limited effective depth, and the evanescent wave of the probe light detects the dynamic behavior in real time. The time response of the photoexcitation in ADDLCs in the pumped ATR experiment is less than 2ms and believed the reaction occur in the local region of 100 nm. This result is a witness of that the reaction in this local region is free of the influence of the elastic continuum of the whole LC cell. With the help of the local sensitivity and local disturbance, the detailed reactions during the photoexcitation process are clearly observed and the dynamics equation are expressed to illustrate the oscillation phenomena of LC directors as the pump light irradiates on this region.

Original languageEnglish
Title of host publicationLiquid Crystals and Applications in Optics
Publication statusPublished - 2007 Nov 23
EventLiquid Crystals and Applications in Optics - Prague, Czech Republic
Duration: 2007 Apr 172007 Apr 18

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherLiquid Crystals and Applications in Optics
Country/TerritoryCzech Republic

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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