Quantum jumps of individual emitters in a heterogeneous environment studied by near-field optics - Quantum Electronics and Laser Science Conference, 2000. (QELS 2000). Technical Digest

Correlatioiis aud spectral properties of thermal light have been the subject of many studies since the developmeut ofstatistical optics aid modern coherence In most of the studies, the nonradiating (near field) part ofthe emitted light is disregarded, because it plays no role in the Car-field emission properties of planar sources. Neveitlieless, recent interest in microscale and nanoscale radiative transfer? together with the development o l local-probe thermal microscopy and the observation of coherent thermal emission from doped silicon and silicon carbide (Sic) gratings? have raised new challenges. In fact, all these topics have in common the substantial role of the non-radiating (evanescent) thermal fields. Spatial correlations of the near field therinally emitted by a planar opaque surlace were studied The strong influence of the non-propagating components of the field was put forward. In particular, it was shown that resonant surface excitations (surface-plasmon or surface-phonon polaritons) lead to longrange spatial correlations.6 This phenomenon is at the origin of spatially-coherent thermal emission of doped silicon and Sic g r a t i ~ g s . ~ In this work, we concentrate on the spectral properties ofthe therinally emitted near field. Our approach is based on fluctuational electrodynamics and the fluctuation-dissipation theorem.2 The basic quantity to compute is the crossspectral density tensor ofthe electric field: