SIGNAL ANALYSIS OF APERTURELESS SCANNING NEAR-FIELD OPTICAL MICROSCOPY WITH SUPERLENS

Field enhancement in apertureless near-field scanning optical microscopy.

The near field of an apertureless near-field scanning optical microscopy probe is investigated with a multiple-multipole technique to obtain optical fields in the vicinity of a silicon probe tip and a glass substrate. The results demonstrate that electric field enhancements of >15 relative to the incident fields can be achieved near a silicon tip, implying intensity enhancements of several orde...

Polarization Properties in Apertureless-Type Scanning Near-Field Optical Microscopy

Polarization properties of apertureless-type scanning near-field optical microscopy (a-SNOM) were measured experimentally and were also analyzed using a finite-difference time-domain (FDTD) simulation. Our study reveals that the polarization properties in the a-SNOM are maintained and the a-SNOM works as a wave plate expressed by a Jones matrix. The measured signals obtained by the lock-in dete...

An analysis of heterodyne signals in apertureless scanning near-field optical microscopy.

This study constructs interference-based model of the apertureless scanning near-field optical microscopy (A-SNOM) heterodyne detection signal which takes account of both the tip enhancement phenomena and the tip reflective background electric field. The analytical model not only provides a meaningful explanation of the image artifacts and errors, but also suggests methods for reducing these ef...

Apertureless scanning near field optical microscope with sub-10nm resolution

Beyond lock-in analysis for volumetric imaging in apertureless scanning near-field optical microscopy.

Conventional apertureless scanning near-field optical microscopy uses lock-in demodulation techniques to filter higher harmonics from the periodically modulated optical signal. On the one hand, this signal notoriously may contain contaminating mechanical contributions; on the other, it reduces the available data to one number per pixel. Realizing that the vertically oscillating near-field probe...