Spectral imaging of single molecules

Using a setup based on fluorescence microscopy we study fluorescence spectra of single chromophores. Being point like emission sources single molecules can be focused to the entrance slit of a spectrometer. Even with narrow slit width the light passes the system with almost no loss. We show that, making full use of the emission properties of a single molecule, fluorescence spectra of many single molecules can be recorded simultaneously using (hyper-)spectral imaging. The vibrational frequencies of the single terrylene chromophores in naphthalene are the same within the accuracy of our experiments but the vibronic lines show pronounced differences in their relative intensities.