用3D-FDTD法分析用于近场光存储的光纤探针电磁波传输特性

提高近场光存储的存储信息密度的关键主要在于掌握近场存储光纤探针的透光率、近场光斑直径尺寸以及场梯度等近场物理量。采用三维时域有限差分 (3D FDTD)法分析了可用于近场光存储的光纤探针尖的光学性质 ,对不同类型光纤的近场光场分布进行了数值计算 ,给出结果并进行比较 ,从光学性质的角度对其在近场光存储中的应用加以讨论。完全镀膜光纤尖在极近场处的光斑可获得 10nm的尺寸 ,远小于传统光纤光学聚焦的光斑尺寸大小。

Electromagnetic Propagation of Fiber Probe for Near-field Optical Recording Using 3-D FDTD Method

The data density of the near field optical recording is mainly determined by near field electromagnetic distribution of probe fiber such as transmission efficiency, near field light spot size, polarization keeping and the grade of the electromagnetic field. The optical characters and light wave propagation of various fiber probes for near field optical recording are numerically simulated using 3D finite difference time domain (3D FDTD) method in this paper. The possible application in near field optical recording with these probes is discussed. The entirely metal coat probe is pointed out to have an extremely small near field spot size about 10 nm, which is far less than that of the conventional probe.