Modelling of liquid crystal diffraction devices

A programmable, high resolution phase spatial light modulator using a liquid crystal on silicon (LCoS) device as a grating, formed from an array of small square pixels and operating in reflection, has been modelled using a combination of methods. The liquid crystal structure and switching behaviour is calculated using a 3D finite elements method based on a vector representation of the liquid crystal director and a variational approach, while the reduced order grating method (RGM), a coupled wave approach, is used to study the optical diffraction from the device.