Near-field optical mapping using light-induced polymermovement

我发现光学梯度力和各向异性光流动性都有助于垂直极化到薄膜表面的光引起聚合物的运动（Ez）。我还发现，通过改变照射光的波长，施加在聚合物主链上而不是侧链偶氮基团上的光学梯度力对聚合物的运动起作用。对于使用光诱导聚合物运动的应用，我对单个金纳米颗粒（50纳米）附近的增强近场分布进行了纳米成像。我发现在金纳米粒子的近两侧沿极化方向形成了倾角。认为各向异性光流使聚合物沿极化方向从高光强区向低光强区移动。由聚合物在聚合物膜表面的运动得到的光强分布与时域有限差分模拟得到的光强分布吻合较好，从而验证了该方法的有效性。

I found that both optical gradient force and anisotropic photo-fluidity contribute to the polymer movement induced by light perpendicularly polarized to the film surface (Ez). I also found by changing the wavelength of the irradiation light that optical gradient force exerted on not side-chain azo moiety but main chain of the polymer contributes to the polymer movement. For applications using light-induced polymer movements, I performed nano-imaging of the enhanced near-field distribution in the vicinity of a single gold nano particle (50 nm). I found the dips are formed along the polarization direction at both near sides of the gold nano particle. It is considered that anisotropic photo-fluidity moves the polymer from high to low light intensity regions along the polarization direction. The light intensity distribution evaluated from the induced polymer movement on the surface of the polymer film is good agreement with one calculated from the FDTD simulation, thus validity of this method can be verified.