Thermo- and electro-optical properties of photonic liquid crystal fibers doped with gold nanoparticles.

Agata Siarkowska,Daniel Budaszewski,Miłosz Chychłowski,Tomasz R Woliński,Bartosz Bartosewicz,Bartłomiej Jankiewicz

doi:10.3762/bjnano.8.278

Abstract

Thermo- and electro-optical properties of a photonic liquid crystal fiber (PLCF) enhanced by the use of dopants have been investigated. A 6CHBT nematic liquid crystal was doped with four different concentrations of gold nanoparticles (NPs), 0.1, 0.3, 0.5 and 1.0 wt %, for direct comparison of the influence of the dopant on the properties of the PLCF. The thermo-optical effects of the liquid crystal doped with gold NPs were compared in three setups, an LC cell, a microcapillary and within the PLCF, to determine if the observed responses to external factors are caused by the properties of the infiltration material or due to the setup configuration. The results obtained indicated that with increasing NP doping a significant reduction of the rise time under an external electric field occurs with a simultaneous decrease in the nematic–isotropic phase transition temperature, thus improving the thermo- and electro-optical properties of the PLCF.

Highlights

Since their discovery in 1888, liquid crystals (LCs) have attracted nonstop research interest for their unique electro-optical properties that are essential in various optical and photonic applications such as LC displays, attenuators, tunable polarizers, spatial light modulators, photonic sensors, etc. [1,2]
Experiments were performed in three different setups to eliminate the possibility that any change in the N–I phase transition temperature is related to the specific setup
For LC cells, the N–I phase transition temperature was taken as the temperature where isotropic droplets appeared in the sample

Summary

Introduction

Since their discovery in 1888, liquid crystals (LCs) have attracted nonstop research interest for their unique electro-optical properties that are essential in various optical and photonic applications such as LC displays, attenuators, tunable polarizers, spatial light modulators, photonic sensors, etc. [1,2]. In the second part of the experiments, we focused only on PLCFs doped with gold NPs. The LC material used for infiltration of the host structure was a nematic 4-(trans-4'-n-hexylcyclohexyl)isothiocyanatobenzene (6CHBT) LC, which has the following parameters at room temperature: ne = 1.67, no = 1.52, Δn = 0.15 and Δε = 8.0.

Results

Conclusion