近场光学技术在高分辨率成像、 光谱探测和纳米加工等领域有广泛应用, 而光纤探针是其中一个关键部件。 如何提高光纤探针的传输效率是近场光学技术应用中的一个重要问题。 本文采用三维时域有限差分方法, 计算了锥形有孔探针的传输效率, 分析了锥角、 针尖孔径、 波长和金属层厚度等因素对光纤探针传输效率的影响, 并比较了裸光纤探针和有金属涂层的光纤探针在传输效率和空间分辨率上的差异。 此外, 还发现了传输效率随入射光波长变化出现的振荡现象。

A fiber probe is the key component of near-field optical technology which is widely used in high resolution imaging, spectroscopy detection and nano processing. How to improve the transmission efficiency of the fiber probe is a very important problem in the application of near-field optical technology. Based on the results of 3D-FDTD computation, the dependence of the transmission efficiency on the cone angle, the aperture diameter, the wavelength and the thickness of metal cladding is revealed. The authors have also made a comparison between naked probe and the probe with metal cladding in terms of transmission efficiency and spatial resolution. In addition, the authors have discovered the fluctuation phenomena of transmission efficiency as the wavelength of incident laser increases.