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Updated: Aug 19, 2026

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
Published on: May 29, 2018
Optical transverse excitation in quaterthiophene crystals by ultraviolet-visible internal and attenuated total
L Raimondo1, M Laicini, S Tavazzi
1Dipartimento di Scienza dei Materiali and INFM, Università di Milano Bicocca, Via Cozzi 53, I-20125 Milano, Italy. luisa.raimondo@mater.unimib.it
Abstract:
We report internal and attenuated total reflection of light at the interface between glass and a quaterthiophene crystal in the spectral region of the electronic transitions. The bands corresponding to the absorption of the a(u) and b(u) Frenkel exciton states are detected for different polarization of the incident light. In particular, the wave-normal vector being almost perpendicular to the b(u) transition dipole moment allows its transverse component to be accessed, whose excitation in conventional external reflection or transmission spectroscopies is forbidden.
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