偏振光调制的扫描近场光学显微镜应用

Application of polarization-modulation near field scanning optical microscope

本文利用电光调制技术结合反射式扫描近场光学显微镜 ,获得了可以对光的偏振方向进行调制的针尖发光远场接收反射光的近场显微镜。对原有的TopometrixAuroraNSOM系统作了较大的改进。采用音叉 (tuningfork)检测光纤探针与样品间的剪切力取代了原有的光学法振动检测 ,避免了杂散光干扰。观察了 (Ba0 5Sr0 5)TiO3薄膜和LiTaO3晶体表面的电畴结构。横向分辨率约为 5 0nm。观察说明 ,反射式扫描近场光学显微镜适合研究固体表面的电畴结构 ,可获得光学衬度较好的电畴分布图像。

A polarization modulation near field scanning optical microscope with electro optic modulator combination was built,and a lateral resolution of 50nm might be achieved.The direction of linearly polarized was modulated and the light was emitted from the probe tip and collected in the far field. A modified Topometrix Aurora NSOM was used in this detection. The tuning fork shear force feedback instead of optical detection was used,so the stray light was greatly reduced. The ferroelectric domain in LiTaO 3 single crystal and the (Ba 0.5 Sr 0.5 )TiO 3 thin film was detected. The reflection mode can give a good resolution and contrast image of domains in the surface of solid samples with little correlation to the topography.