title: Electro-optic properties of switchable gratings made of polymer and nematic liquid-crystal slices.
abstract: We report the diffraction properties at wavelengths of 632.8 and 1550 nm for volume transmission gratings made of a sequence of continuously aligned nematic liquid-crystal layers separated by isotropic polymer slices. The gratings are generated by holographically curing a solution of liquid crystal diluted in an isotropic prepolymer by means of a laser beam at a wavelength of 352 nm with a total intensity of approximately 10 mW/cm2. A diffraction efficiency of 98% was measured, and an electric field as low as 5 V/microm switches off the phase grating. Measured angular spectra are fitted by use of the modified coupled-mode theory including the effects of grating birefringence.
authors.affiliation: Department of Electronic Engineering, University of Rome La Sapienza, National Institute for the Physics of Matter, Via Eudossiana 18, 00184 Rome, Italy. antonio.dalessandro@uniroma1.it
authors.forename: A
authors.initials: A
authors.lastname: d'Alessandro
authors.forename: R
authors.initials: R
authors.lastname: Asquini
authors.forename: C
authors.initials: C
authors.lastname: Gizzi
authors.forename: R
authors.initials: R
authors.lastname: Caputo
authors.forename: C
authors.initials: C
authors.lastname: Umeton
authors.forename: A
authors.initials: A
authors.lastname: Veltri
authors.forename: A V
authors.initials: AV
authors.lastname: Sukhov