Numerical Simulation of Fiber Probe Patterns of SNOM Using FDTD Method

The resolution capability of the fiber probe in SNOM is determined mainly by probe parameters of cone angle, apex diameter and metal coat thickness for coated probe. The optical characters and light wave propagation of various fiber probes for SNOM with different profiles are analyzed using finite-difference time-domain (FDTD) method in this paper. The dependence on the shape of the probe, taper angle, and metal thickness in front of the tip is investigated for the power transmission and resolution through the probe. The femtosecond light pulse propagation process in fiber probe is also described. This method can be used to optimize the shape of fiber probe and help to design novel probes of SNOM.