Optimising response of liquid crystal corrector with digital overdriving technique

Abstract

Digital overdriving technique is used to enhance response performance of liquid crystal device for wave front correction, combined with electro-optic effect. Generally, using phase wrapping technique, liquid crystal wave front correction only needs 1λ phase retardation. In this new driving scheme, it was increased to 1.2λ and only the phase retardation from 0 to 1λ was used for real correction. Different from conventional method, transition grey level is needed for each grey level as to accelerate its response. This method could enhance the response time up to 50% and unify all the grey-to-grey responses to one equal value. It can be easily implemented into every conventional Liquid Crystal devices without any additional hardware modification. A liquid crystal on silicon device with synthesised liquid crystal material by our lab was used to demonstrate its feasibility. After optimisation, the response time was reduced from nearly 3.3 ms down to 1.55 ms.