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Near-field circular polarization probed by chiral polyfluorene
M Savoini1, P Biagioni, G Lakhwani
1Dipartimento di Fisica-CNISM, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
Optics Letters
|November 21, 2009
Summary
Researchers achieved high circular polarization in scanning optical microscopy near fields using chiral polymer films. This breakthrough enables new nano-optics applications with circularly polarized near fields.
Area of Science:
- Optics and Photonics
- Materials Science
- Nanotechnology
Background:
- Scanning optical microscopy relies on precise light control.
- Delivering circularly polarized light to the near field is challenging.
- Chiral materials offer unique optical properties.
Purpose of the Study:
- To demonstrate high circular polarization delivery to the near field of scanning optical microscopy probes.
- To investigate the role of chiral polymer films in achieving this polarization.
- To explore the dependence of near-field polarization on aperture shape.
Main Methods:
- Utilizing hollow-pyramid probes for scanning optical microscopy.
- Analyzing the dichroic properties of annealed thin polymer films with chiral polyfluorene derivatives.
- Placing the polymer film in close proximity to the optical probe's aperture.
Main Results:
- Achieved a high degree of circular polarization in the probe's near field.
- Demonstrated that near-field polarization is largely independent of aperture shape.
- Confirmed the effectiveness of chiral polyfluorene derivatives in the polymer film.
Conclusions:
- High circular polarization can be effectively delivered to the near field of scanning optical microscopy probes.
- Chiral polymer films are a viable method for generating circularly polarized near fields.
- This technique opens possibilities for advanced nano-optics applications.
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