In the nematic cell with chiral dopant and homeotropic anchoring can exist
the next one-dimensional distributions of the director: 1) homeotropic, wit
h the director normal to the plates: 2) twisted with tilted orientation of
the director; 3) twisted with the director parallel to the surfaces. Stabil
ity analysis shows that the transitions might occur between these distribut
ions. The dimensionless parameters controlling the director field are the r
atio of the pitch of the twisted nematic structure to the cell thickness an
d ratio of the cell thickness to thr;extrapolation length of the nematic ma
terial.