Electrically tunable properties of wideband-absorptive and reflection-selective films based on multi-dichroic dye-doped cholesteric liquid crystals

Abstract

This work demonstrated an electrical switch of thin film with Bragg reflection and wideband light absorption characteristics based on three commercially available azobenzene-dichroic dye-doped cholesteric liquid crystals (LCs). The effect of the pitch of cholesteric LCs on their electro-optical characteristics and laser protection properties (λ = 532 nm) was investigated in detail. Experimental results showed that such electrically tunable films had advantages of a fast response time, a polariser-free, low power consumption and high transmittance. Moreover, the transmittance of the thin films can be easily modulated by applying an electric field. It therefore exhibited the potential application as laser protective systems against the damage to the sensor or human’s eye from a laser.

Keywords:

• cholesteric liquid crystals
• azo-dichroic dye
• electro-optical properties
• wideband absorption
• selective reflection
• laser protection

Additional information

Funding

This work was supported by the Major Project of International Cooperation of the Ministry of Science and Technology [grant number 2013DFB50340]; the National Natural Science Foundation [grant number 51333001], [grant number 51173017]; the Major Program of Chinese Ministry of Education [grant number 313002]; the Doctoral Fund of Chinese Ministry of Education [grant number 20120001130005]; the Project of Guiyang Science and Technology Program [grant number [2012205]6-1].