Strong extinction of a laser beam by a single molecule
  We present an experiment where a single molecule strongly affects the amplitude and phase of a laser field emerging from a subwavelength aperture. We achieve a visibility of -6% in direct and +10% in cross-polarized detection schemes. Our analysis shows that a close to full extinction should be possible using near-field excitation. 
I. Gerhardt, G. Wrigge, P. Bushev, G. Zumofen, R. Pfab, V. Sandoghdar