Apertureless scanning near-field optical microscopy: the need for probe-vibration modeling

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Apertureless scanning near-field optical microscopy (ASNOM) utilizes probe vibration to amplify detected signals.
• Signal detection in ASNOM relies on lock-in amplifiers tuned to the probe-vibration frequency.

Purpose of the Study:

• To develop and validate a realistic numerical model for ASNOM.
• To investigate the key physical parameters influencing signal detection in ASNOM.

Main Methods:

• Two-dimensional numerical simulations of ASNOM were performed.
• Numerical results were compared with experimental scan data.

Main Results:

• A realistic ASNOM model requires incorporating probe scanning dynamics.
• Probe vibration amplitude and frequency are critical factors.
• Material properties of the sample significantly affect the detected signal.

Conclusions:

• Accurate prediction of ASNOM signals necessitates a comprehensive model.
• The model must account for probe movement, vibration, and the optical properties of the sample.