Near-field optical virtual probe based on evanescence wave interference and nano-aperture

摘要

Near-field optical virtual probe (NFOVP) is a kind of immaterial tip based on evanescence wave interference and nano-aperture diffraction, which has great potential in near-field optical data storage, nano-lithography, near-field optical imaging and spectral detection, near-field optical manipulation and etc.. In this paper, the characteristics of NFOVP have been revealed through numerical simulation by the method of 3-D Finite-Difference Time-Domain (FDTD) and vector diffraction. The simulation results show that the transmission efficiency is higher than that of nano-aperture metal-coated fiber probe widely used in near-field optical systems. The FWHM of central peak, in other words, the size of near-field virtual probe is constant whatever the distance increases in a certain range so that the critical nano-separation control in near-field optical system can be relaxed. A realization model of NFOVP in solid immersion lens system has been proposed. The influences of some factors of NFOVP, such as the shape and size of aperture, polarization and etc. have been analyzed. And the results also show that sidelobe suppression may depend on optimization of aperture function and incident beams of NFOVP.