Design and performance of a versatile holographic liquid-crystal wavelength-selective optical switch

We present here a theoretical analysis and the experimental evaluation of a wavelength-selective optical space switch based on three-dimensional beam steering using the diffractive liquid-crystal (LC) technology. Here, many advantages are combined within the same device. First, the motionless operation of diffractive LC devices provides stable, accurate, and reproducible switching maps, as well as a very simple addressing and supervision scheme. Then, it is shown both qualitatively and quantitatively that diffractive (or holographic) structures enable the extension of the device functionalities to multicast switching and variable-wavelength-band selection. This represents a first step toward compact optical routing nodes and merging wavelength- and space-routing capabilities.