A review of nonlinear optical properties of nematic liquid crystals

We present a review of the electronic and non-electronic optical nonlineari ties of nematic liquid crystals (NLC), and recently observed nonlinear opti cal processes. In both the ordered and isotropic phases, NLCs exhibit large optical nonlinearities with response times ranging from picoseconds to mil liseconds. The fundamental principles underlying these nonlinearities, thei r dynamics and practical application potential are discussed. Comparisons a re made with other nonlinear optical materials currently being investigated .