abstract
We use the magnetic field distribution of an azimuthally polarized focused laser beam to excite a magnetic dipole transition in Eu3+ ions embedded in a Y2O3 nanoparticle. The absence of the electric field at the focus of an azimuthally polarized beam allows us to unambiguously demonstrate that the nanoparticle is excited by the magnetic dipole transition near 527.5 nm. When the laser wavelength is resonant with the magnetic dipole transition, the nanoparticle maps the local magnetic field distribution, whereas when the laser wavelength is resonant with an electric dipole transition, the nanoparticle is sensitive to the local electric field. Hence, by tuning the excitation wavelength, we can selectively excite magnetic or electric dipole transitions through optical fields.
keywords
CYLINDRICAL-VECTOR BEAMS; ENERGY-TRANSFER; NANOCRYSTALS; EU3+; LUMINESCENCE; EU3+-Y2O3; EMISSION; LIGHT; FIELD; Y2O3
subject category
Physics
authors
Kasperczyk, M; Person, S; Ananias, D; Carlos, LD; Novotny, L
our authors
Duarte Ananias
Assistant Researcher
Luís Carlos
Full professoracknowledgements
The authors acknowledge Palash Bharadwaj for many fruitful discussions. L. N. thanks the Swiss National Science Foundation (SNF) for financial support through Grant No. 200021_149433. L. D. C. and D. A. thank Fundacao para a Ciencia e a Tecnologia (Portugal), EU/FEDER and COMPETE, Contract No. PEST-C/CTM/LA0011/2013.