Electro-switchable characteristics of broadband absorptive films based on multi-dichroic dye-doped nematic liquid crystal

Thin films of a nematic liquid crystal doped with three commercially available azobenzene dichroic dyes were successfully fabricated and their electro-optical properties as well as their selective optical absorptive characteristics were explored in detail. The experimental results showed that the films had a lower and higher transmittance of incident light across the whole visible region without and with an electric field applied, respectively. The transmittance of the light decreased with the increase in both the dye-doped concentration and the cell thickness. Moreover, the transmittances of the films from a continuous wave lasers (λ = 532 nm) were also studied, which exhibited the potential application as a laser protective material to protect against the damage to the sensor or human’s eye from a laser.