SUBWAVELENGTH SPECTROSCOPY, EXCITON SUPERTIPS AND MESOSCOPIC LIGHT-MATTER INTERACTIONS

Subwavelength optical light sources and probes are leading to new devi ces, technologies and techniques such as near-field microscopy, spectr oscopy and biochemical sensing. We have prepared nanometer light sourc es as small as 40 nm in diameter and exciton sources that are even sma ller by adding various inorganic and organic crystals and molecularly doped polymers to micropipettes and nanofabricated fiber-optic tips. W e demonstrate subwavelength spectroscopy with highly spatially resolve d fluorescence spectral of nanocrystals (perylene) in polymeric glasse s (PMMA). We also demonstrate an interfacial Kasha (external heavy-ato m) effect on a perylene nanocrystal surface. We give results on near-f ield optics and energy transfer at interfaces of nanocrystals (anthrac ene or diphenyl-anthracene) and dyes (rhodamine B) or dyes embedded in Langmuir-Blodgett films. We discuss the rise of new phenomena when th e light source and the sample form a combined mesoscopic system, with subsequent quantum optics effects.