All-optical switching in holographic polymer dispersed azobenzene liquid-crystal gratings

摘要

We report an all-optical switching transmission grating fabricated by holographic polymer dispersed liquid crystal (H-PDLC) technique. The all-optical switching ability is achieved by doping the nematic LC with azobenzene. The trans-cis deformation of doped azobenzene under the irradiation of pumping light induces the phase transformation of the phase-separated LC microdomains and further creates an index modulation environment to switch the grating efficiency. We also observe the grating formation by monitoring the diffracted intensity at different writing laser power. An optimum of writing power (150 mW/cm~2) is required to get maximum diffraction efficiency.