Dynamics of biphotonic intensity holographic gratings based on dye-doped liquid crystal films

The dynamics of biphotonic intensity holographic gratings (BIHGs) based on dye-doped liquid crystal (DDLC) films, including optical and thermal effects, are studied. Experimental results indicate that the formation of a BIHG involves bulk reorientation and surface adsorption. The former yields a transient biphotonic grating; the latter results in a persistent biphotonic grating. Additionally, the dynamic behaviours of the biphotonic diffraction signals are different from those of a conventional one-photonic diffraction signal, and depend on the intensity(polarization) of the green(red) pump-beam. The effect of ambient temperature on the diffraction efficiency of a BIHG is also studied: a higher ambient temperature prevents more dye molecules from being adsorbed on the substrate.