This study is aimed to determine the influence of the size of gold (Au) nanoparticles (NP) doped in azopolymer PAZO (poly[1-[4-(3-carboxy-4-hydroxyphenylazo) benzenesulfonamido]-1,2-ethanediyl, sodium salt]) on the photoinduced birefringence of the nanocomposite thin films as well as on the diffraction efficiency of polarization holographic gratings recorded in them. For this reason, we used spherical Au NP with five different dimensions – 10, 20, 30, 40 and 50 nm. Concentrations of the NP in the nanocomposites varied from 0 a.u. (non-doped samples) to 16 a.u. where 1 a.u. corresponds to 0.015 wt %. Birefringence was induced with He–Cd laser (λ = 442 nm) and measured at 635 nm using DPSS laser. We observe an enhancement of photoinduced birefringence, which is most pronounced for the Au NP with size 20 nm. The polarization holographic gratings were inscribed with two orthogonal circular polarizations (left- and right-handed). AFM measurements were performed to determine the properties of the resulting surface relief gratings. Our results indicate that both the diffraction efficiencies and surface relief modulation of the gratings inscribed in the nanocomposite thin films are higher compared to those in the non-doped samples.

本研究旨在确定掺杂在偶氮聚合物 PAZO（聚[1-[4-（3-羧基-4-羟基苯基偶氮）苯磺酰胺]-1,2-乙二基，钠盐]）对纳米复合薄膜的光致双折射以及其中记录的偏振全息光栅的衍射效率的影响。出于这个原因，我们使用了五种不同尺寸的球形 Au NP——10、20、30、40 和 50 nm。纳米复合材料中 NP 的浓度从 0 au（未掺杂样品）到 16 au，其中 1 au 对应于 0.015 重量％。双折射由 He-Cd 激光（λ = 442 nm）诱导，并使用 DPSS 激光在 635 nm 处测量。我们观察到光致双折射的增强，这对于尺寸为 20 nm 的 Au NP 最为明显。偏振全息光栅刻有两个正交的圆偏振（左旋和右旋）。进行 AFM 测量以确定所得表面浮雕光栅的特性。我们的结果表明，与未掺杂的样品相比，刻在纳米复合薄膜中的光栅的衍射效率和表面起伏调制都更高。