Citation
Geday, Morten Andreas and Campo, Guillermo del and Carrasco-Casado, A. and Bennis, Noureddine and Quintana Arregui, Patxi Xabier and López Hernández, Francisco and Otón Sánchez, José Manuel
(2008).
V-Shape Liquid Crystal-Based Retromodulator Air to Ground Optical Communications.
"Molecular Crystals and Liquid Crystals", v. 494
;
pp. 213-221.
ISSN 1542-1406.
https://doi.org/10.1080/15421400802430299.
Abstract
This paper describes the use of a 2D liquid crystal retro-modulator as a free space, wireless, optical link. The retro-modulator is made up of a retro-reflecting cornercube onto which 2 cascaded V-shape smectics liquid crystal modulators are mounted. The communication link differs with respect to more conventional optical links in not using amplitude (nor frequency) modulation, but instead state-of-polarisation (SOP) modulation known as Polarisation Shift Keying (PolSK). PolSK has the advantage over amplitude modulation, that it is less sensitive to changes in the visibility of the atmosphere, and increases inherently the bandwidth of the link. The implementation of PolSK both in liquid crystal based and in retro-modulated communication are novelties.
