SNOM Probe Based on Nano-Antenna with Large Aperture and High Resolution

Abstract

We present a probe of scanning near-field optical microscope (SNOM) with large aperture and high resolution, which is added a metallic dipole nano-antenna onto the tip of the ordinary probe. Based on the FDTD algorithm we investigate numerically the measure results by different aperture probes for the same sample with the incident wavelength of 830nm and the scan height of 10nm. The results show that the resolution of the new probe is 100nm, 75nm, 50 nm, 45 nm, 50 nm, 70nm when the probe aperture is 50nm, 100nm, 130nm, 150nm, 170nm, 200nm respectively, and for the ordinary probe the resolution is 50nm，120 nm,140 nm,180 nm, 200nm, 220nm correspondingly. That is to say the resolution of the ordinary probe decrease rapidly with the increasing of the aperture, however the novel probe can maintain the high resolution.