Dislocation profile in cholesteric finger texture.

The displacement field around an isolated elementary dislocation in a medium with one-dimensional periodicity is established experimentally. The system studied is a cholesteric fingerprint texture with a macroscopic ( approximately 10 microm) periodicity. The characteristic elastic length is smaller than the "interlayer" distance. As a result, the experimental dislocation profile deviates from the classic pattern predicted by the linear elastic theory but fits well with the recently suggested nonlinear theory of dislocation [Phys. Rev. E 59, R4752 (1999)].