Cholesteric gratings doped with a dichroic dye

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