A single ion as a nanoscopic probe of an optical field

Citation
Gr. Guthohrlein et al., A single ion as a nanoscopic probe of an optical field, NATURE, 414(6859), 2001, pp. 49-51
Citations number
21
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary,Multidisciplinary,Multidisciplinary
Journal title
NATURE
ISSN journal
0028-0836 → ACNP
Volume
414
Issue
6859
Year of publication
2001
Pages
49 - 51
Database
ISI
SICI code
0028-0836(20011101)414:6859<49:ASIAAN>2.0.ZU;2-C
Abstract
In near-field imaging, resolution beyond the diffraction limit of optical m icroscopy is obtained by scanning the sampling region with a probe of subwa velength size(1). In recent experiments, single molecules were used as nano scopic probes to attain a resolution of a few tens of nanometres(2,3). Posi tional control of the molecular probe was typically achieved by embedding i t in a crystal attached to a substrate on a translation stage. However, the presence of the host crystal inevitably led to a disturbance of the light field that was to be measured. Here we report a near-field probe with atomi c-scale resolution-a single calcium ion in a radiofrequency trap-that cause s minimal perturbation of the optical field. We measure the three-dimension al spatial structure of an optical field with a spatial resolution as high as 60 nm (determined by the residual thermal motion of the trapped ion), an d scan the modes of a low-loss optical cavity over a range of up to 100 mum . The precise positioning we achieve implies a deterministic control of the coupling between ion and field. At the same time, the field and the intern al states of the ion are not affected by the trapping potential. Our set-up is therefore an ideal system for performing cavity quantum electrodynamics (4,5) experiments with a single particle.