Effect of TiO2 nanoparticle doping on the performance of electrically-controlled nematic liquid crystal core waveguide switch

Abstract A liquid crystal (LC) core waveguide has been designed and fabricated using nanocolloid of the nematic liquid crystal 5CB, doped with TiO 2 nanoparticles, as the core. Nematic liquid crystals doped with small amount of nanoparticles can have significantly altered electro-optic response. The performance of the fabricated LC core waveguide as an optical-switch has been studied, and the experimental result shows that the threshold voltage for switching is reduced from 1 V to 0.25 V due to TiO 2 nanoparticle dopant-concentration of 2.0 wt.%. The overall optimal performance of the waveguide switch, in terms of threshold voltage, extinction ratio, and response time, is achieved for a dopant-concentration of 0.5 wt.%.