LIQUID CRYSTALS IN TELECOMMUNICATIONS SYSTEMS

The first liquid crystal devices have recently been installed in the fibre optic networks that provide the backbone of the modern telecommunications system. Most optical network devices are concerned with the manipulation of the amplitude and phase of the optical signal. Liquid crystals have the highest figure of merit for field addressed electro-optic response and can have excellent transparency in the optical telecommunications window. Here we consider the importance of liquid crystals in controlling the phase and the state of polarisation of light in these systems. We also consider arrays of liquid crystal phase modulators, fabricated using LCOS technology, in holographic switches and multifunction devices.