Dynamical behaviour of holographic gratings with a nematic film --Polymer slice sequence structure
INFM Unitá di Napoli and Dipartimento di Scienze Fisiche, Universitá di Napoli Federico II, Via Cinthia, 80126, M. S. Angelo, Napoli, Italy
2 Liquid Crystal Laboratory LICRYL, INFM Unitá di Cosenza CEMIF-CAL, Centro di Eccellenza and Dipartimento di Fisica, Universitá della Calabria, 87036, Arcavacata di Rende (CS), Italy
We have studied the dynamical response of a new kind of holographic grating to a pulsed electric field. The structure, named POLICRYPS, consists of a sequence of homogeneous polymer slices separated by liquid-crystal films. We have found that both the rise and fall response times depend on the pulse duration and amplitude of the applied electric field. We propose a phenomenological explanation for this behaviour, outlining the possibility of getting response times of the order of 100 s by properly choosing the pulse shape. Results are very interesting for developments in which POLICRYPS gratings could be proposed as basic elements in photonic devices for telecom applications, and induce to a deeper analysis of the microscopic interaction between liquid crystal and polymer interfaces in these samples.
© EDP Sciences, Società Italiana di Fisica, and Springer-Verlag, 2004