Electrohidrodinámica de cristales líquidos nemáticos

This paper presents an analytical formalism that allows for a description of a variety of non linear optical phenomena occurring when an electromagnetic wave propagates through a nematic liquid crystal. First, by using only thermodynamic and symmetry properties, a closed set of hydrodynamic equations is constructed, which provides for a complete description of the dynamics of a low molecular weight nematic in the absence of external fields. Then these equations are generalized to include an external electromagnetic field propagating through the fluid. The coupled and non linear character of the equations is discussed, and a method of iterative and systematic approximations in powers of parameters with a well defined physical interpretation is proposed. The advantages as well as the limitations of the approach are also discussed.