High birefringence liquid crystal mixtures for laser beam steering

Summary form only given. Optical phased arrays (OPA) represent a versatile device for laser beam steering, adaptive optics, electronic lens, and network switching. An applied stepwise voltage creates a phase grating inside the liquid crystal (LC) media that deflects the incoming laser beam to a programmable angle with high precision and high energy efficiency. LC mixtures with Δn≥0.4 and low viscosity, wide nematic range, low operating voltage and good UV stability are particularly desirable. Tolane liquid crystals exhibit a reasonably high Δn, low viscosity, and good chemical, photo and thermal stability. The same properties are also found in isothiocyanates. Therefore, coupling tolane and NCS groups should lead to a high birefringence and large dielectric anisotropy while preserving a relatively low viscosity.