Cholesteric gratings doped with a dichroic dye

We report the results obtained from the studies of cholesteric gratings dop ed with a dichroic guest-host dye, G206. First, a dye-doped planar choleste ric texture was switched to a fingerprint texture. Using the pump (Ar+ lase r)-probe (Ile-Ne laser) technique, we then studied the diffraction characte ristics of the Raman-Nath cholesteric grating. The results showed that the diffraction efficiencies of the first- and second-order diffracted beams de creased and increased, respectively, with increasing power of the pump beam , while those of the zeroth order remained unchanged. In addition, the diff racted beams can be steered using the pump beam. We propose a model based o n the thermal effect resulting from the dye absorption of the pump beam. It explains the experimental results qualitatively well.