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Stimulated Stokes and Antistokes Raman Scattering in Microspherical Whispering Gallery Mode Resonators
Published on: April 4, 2016
Virtual resonance and frequency difference generation by van der Waals interaction
Physical Review Letters
|June 4, 2011
Summary
Synthesized mode atomic force microscopy can image material interiors. Optimal imaging occurs when the nonlinear force is tuned to van der Waals interactions, enhancing probe oscillations for better detection of material inhomogeneities.
Area of Science:
- Materials Science
- Nanotechnology
- Physics
Background:
- Atomic Force Microscopy (AFM) is a key tool for nanoscale imaging.
- Exploring material interiors for inhomogeneities requires advanced AFM techniques.
- Mode synthesizing AFM offers new possibilities for subsurface imaging.
Purpose of the Study:
- To investigate the optimal conditions for difference frequency (ω_) generation in synthesized mode AFM.
- To understand the role of nonlinear forces in enhancing probe oscillations.
- To validate theoretical predictions with experimental results for subsurface material analysis.
Main Methods:
- Development of a semiempirical nonlinear force model for AFM.
- Parametric study of probe-sample excitation at difference frequencies.
- Experimental validation of the ω_ generation model.
Main Results:
- Difference frequency (ω_) generation is optimal when the nonlinear force is tuned to van der Waals form.
- Predicted ω_ oscillations show excellent agreement with experimental data.
- The concept of virtual resonance is introduced to explain enhanced probe oscillations.
Conclusions:
- Synthesized mode AFM provides a powerful method for exploring material interiors.
- Tuning nonlinear forces to van der Waals interactions maximizes ω_ generation.
- Virtual resonance offers a mechanism for significantly enhancing probe oscillations for improved subsurface imaging.
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