纳米生物领域对光纤探针技术的要求

Demand on the techniques of the fiber probe in the nanometer biological field

扫描近场光学显微镜由于其超过常规光学显微镜的光学分辨能力及特殊功能,正在受到生命科学研究人员越来越多的关注。用时域有限差分法对三维光纤探针的Maxwell方程直接进行求解,获得了光纤探针的光强分布。计算结果表明,光纤探针中的光强分布呈固定的花样图形,其图形形状与光的偏振及针尖的结构有关,故对腐蚀锥和熔拉锥的传输特性进行分析比较,提出了在纳米生物领域对光纤探针的技术要求。

The scanning nearfield optical microscope has superresolution in comparison with conventional optical microscopes and is attracting more and more notice from life scientists. In this paper,a threedimensional(3D) probe model is investigated by solving Maxwell equations with the finitedifference timedomain method. The 3D computation reveals that some patterns of field distributions of light in the probe are formed due to the polarization of light and the structure of the probe. Transmission properties of two kinds of fiber probes,the etched taper and pulled taper,have been compared and the demand on the techniques of the fiber probe in the nanometer biological field has been discussed.