提出两种同时满足高分辨、高传光效率的探针模型以及制备方法: 先用自制热拉装置将光纤拉制成过渡区为双曲线或抛物线形的探针,然后用40%氢氟酸进行快速腐蚀,使探针孔径变小而保持过渡区域形状和锥度基本不变。所获探针孔径变化范围为20～200 nm,锥度20°～60°。为检验探针性能,将两种探针的出射光分布与用传统热拉法所得到探针进行对比;探测了光子扫描隧道显微镜状态下的倏逝波衰减曲线;给出了用集光式扫描近场光学显微镜得到的近场光学图像;同时,验证了探针对剪切力控制的适用性。

Two probe models are presented,which satisfy the conditions of high optical resolution together with high transmission efficiency.A two-step method to fabricate the two kinds of probes is proposed.First,an optical fiber probe with the transitional taper in hyperbolic or parabolic shape is produced by heating-pulling method in a simple home-made device,followed by a rapid chemical etching in 40% buffered hydrofluoric acid to sharpen the tips,keeping the shape and conic angle unchanged.The tips diameters are in the range of 20～200 nm,and the taper angle 20°～60°.To demonstrate the performance of high transmission efficiency of the tips,their spot distributions are compared with conventional taffy-pulled probes.The evanescent wave decay curve in PSTM mode and the scanning near-field image of holographic grating are given by use of transmission SNOM working in collection mode.In addition,an approach curve of shear force is shown to verify its applicability to tip-sample distance regulation based on the shear-force principle.