Abstract

Efficient, reliable and low power optical phase shifters are required in many applications of photonic integrated circuits. Thanks to their large birefringence, liquid crystals are an interesting material for obtaining large phase shifts with low voltages. Due to the high index difference between liquid crystal and silicon, the mode overlap is often small and the tuning effect limited. It is important to consider configurations in which there is a large mode overlap or periodic configurations that can enhance the electro-optic effect. We review a number of interesting configurations and discuss the need for accurate simulations of the liquid crystal behavior, both in two dimensional and three dimensional geometries. Next to maximising the tuning efficiency, it is important to keep the losses introduced by the liquid crystal minimal. We present accurate measurements of the scattering induced by liquid crystal and discuss theoretical models to estimate the amount of light scattering as a function of applied voltages

Related Research Topics

• Liquid Crystals for nanophotonic applications