de Melo P B, Nunes A M, Omena L, do Nascimento S M S, da Silva M G A, Meneghetti M R, de Oliveira I N
Instituto de Física, Universidade Federal de Alagoas 57072-970 Maceió-AL, Brazil.
Instituto de Química e Biotecnologia, Universidade Federal de Alagoas 57072-970 Maceió-AL, Brazil.
Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Oct;92(4):042504. doi: 10.1103/PhysRevE.92.042504. Epub 2015 Oct 15.
The present work is devoted to the study of the thermo-optical and nonlinear optical properties of smectic samples containing gold nanoparticles with different shapes. By using the time-resolved Z-scan technique, we determine the effects of nanoparticle addition on the critical behavior of the thermal diffusivity and thermo-optical coefficient at the vicinity of the smectic-A-nematic phase transition. Our results reveal that introduction of gold nanoparticles affects the temperature dependence of thermo-optical parameters, due to the local distortions in the orientational order and heat generation provided by guest particles during the laser exposure. Further, we show that a nonlinear optical response may take place at temperatures where the smectic order is well established. We provide a detailed discussion of the effects associated with the introduction gold nanoparticles on the mechanisms behind the thermal transport and optical nonlinearity in liquid-crystal samples.
本工作致力于研究含有不同形状金纳米粒子的近晶相样品的热光和非线性光学性质。通过使用时间分辨Z扫描技术，我们确定了纳米粒子添加对近晶A-向列相转变附近热扩散率和热光系数临界行为的影响。我们的结果表明，由于激光照射期间客体粒子提供的取向序局部畸变和热生成，金纳米粒子的引入会影响热光参数的温度依赖性。此外，我们表明在近晶序良好建立的温度下可能会发生非线性光学响应。我们详细讨论了与引入金纳米粒子相关的影响对液晶样品中热传输和光学非线性背后机制的作用。
