Strong Light Extinction by a Single Molecule

In this paper direct measurements of light extinction by single molecules are reported. We use both near-field aperture tips and confocal microscopy at cryogenic temperature to tightly confine the excitation light to an area comparable to the absorption cross section of a single molecule, which results in directly observable 10% extinction of the laser beam. It is concluded that the access to both the incoherent and coherent emission of single molecules opens up a broad range of studies on the light-matter interaction of single solid state emitters.