Electro-optical properties of low viscosity driven holographic polymer dispersed liquid crystals

• Viscosity decreased by ca 1/4 with the addition of 3% triallyl isocyanurate (TI).
• TI eliminated induction period and augmented initial grating formation rate.
• Saturation RDE increased over 200% and Vth decreased to 1/2 with 3% TI.
• Low viscosity TI showed high RDE, high miscibility TI low characteristic voltages.
• Grating is favored by low viscosity, electro-optical performances by miscibility.

Relative diffraction efficiency (RDE), operating voltage, and response times are most important performance characteristics of holographic polymer dispersed liquid crystals (HPDLC). Two types of triallyl isocyanurate (TI) having different structures were incorporated into the conventional transmission grating of HPDLC. Premix viscosity decreased by 13–18% with up to 3% TI, beyond which it increased. TI eliminated induction period and augmented initial grating formation rate at all contents. Saturation RDE increased over 200% while threshold voltage and rise time decreased to about half and 2/3, respectively up to 3% TI, beyond which the tendencies were reversed. Among the two TIs, low viscosity monomer (TA) showed high RDE, while high miscibility monomer (TE) low characteristic voltages and short response times. It is concluded that grating formation is largely favored by low viscosity, while interface tensions and electro-optical performances by miscibility at similar viscosities.