Scanning near-field optical coherent spectroscopy of single molecules at 1.4 K.

We present scanning near-field extinction spectra of single molecules embedded in a solid matrix. By varying the tip-molecule separation, we modify the line shape of the spectra, demonstrating the coherent nature of the interaction between the incident laser light and the excited state of the molecule. We compare the measured data with the outcome of numerical calculations and find a very good agreement.