Near-field circular polarization probed by chiral polyfluorene.
We demonstrate that a high degree of circular polarization can be delivered to the near field (NF) of an aperture at the apex of hollow-pyramid probes for scanning optical microscopy. This result is achieved by analyzing the dichroic properties of an annealed thin polymer film containing a chiral polyfluorene derivative, placed in close proximity to the optical probe. We also prove that the degree of circular polarization in the probe NF does not depend in a significant way on the shape of the aperture, at variance with the far-field behavior. These results demonstrate the feasibility of nano-optics applications exploiting circularly polarized NFs.
Savoini
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Dipartimento di Fisica-CNISM, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
Biagioni
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Lakhwani
G
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Meskers
S C J
SC
Duò
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Finazzi
M
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