A simple implementation of modulation of the near-field optical signal of near-field probes based on the shear-force feedback system is demonstrated in a reflection-mode near-field optical microscope. The modulation exhibits a derivative type of dependence on the near-field signal and no sensitivity to topography. It is shown that the modulation image can be calculated directly from the derivative of the conventional near-field scattering image. This type of near-field modulation is an excellent way to reject far-field artifacts from the near-field signal. Copyright (C) 2000 Elsevier Science B.V.
Bibliographical noteFunding Information:
This work has been supported by NSF/DMR-9816404 and by Seagate Recording Heads. Francis Guillaume carried out the confocal imaging of the samples.
- Derivative image
- Near field modulation