Elliptic shear applied to a homeotropically oriented nematic
above the electric bend Freedericks transition (FT) generates slow precession
of the director. The character of the accompanying nonlinear waves changes
from diffusive phase waves to dispersive ones exhibiting spirals
and spatio-temporal chaos as the FT is approached from above (see Fig.
1.). An exact solution of the flow alignment equations captures the observed
precession and predicts its reversal for non-flow aligning materials. The
FT transforms into a Hopf bifurcation opening the way to understand the
wave phenomena. The dependence of the precession frequency on the destabilizing
electric voltage and on the ellipticity (insert) is shown on Fig. 2.