Related Experiment Videos
Near-field imaging of surface-enhanced second harmonic generation
I I Smolyaninov1, C H Lee, C C Davis
1Electrical Engineering Department, University of Maryland, College Park 20740, USA.
Journal of Microscopy
|June 5, 2001
Summary
Surface-enhanced second harmonic generation was measured from defects on gold films and gratings using a near-field optical microscope. Results were compared with theoretical calculations for optical properties.
Area of Science:
- Nonlinear Optics
- Surface Science
- Nanophotonics
Background:
- Second harmonic generation (SHG) is a nonlinear optical process where two photons interact with a material to produce one photon at double the frequency.
- Surface enhancement of SHG is crucial for sensitive detection and imaging applications.
- Understanding SHG from topographical features is key to controlling light-matter interactions at the nanoscale.
Purpose of the Study:
- To investigate surface-enhanced second harmonic generation (SE-SHG) from specific topographical defects on a gold film.
- To study SE-SHG from metal-coated diffraction gratings.
- To compare experimental SE-SHG field distributions with theoretical predictions.
Main Methods:
- Utilized a near-field optical microscope to measure SE-SHG.
- Fabricated a flat gold film with individual topographical defects.
- Prepared metal-coated diffraction gratings for SE-SHG measurements.
Main Results:
- Successfully measured SE-SHG from individual topographical defects on the gold film.
- Observed distinct SE-SHG field distributions from different defect types.
- Obtained SE-SHG patterns from metal-coated diffraction gratings.
- Found good agreement between experimental and theoretical calculations of SHG field distributions.
Conclusions:
- Topographical defects on gold films can act as localized sources for enhanced second harmonic generation.
- Near-field optical microscopy is effective for mapping nanoscale SE-SHG phenomena.
- Theoretical models can accurately predict SHG behavior from structured surfaces.