Dibenzoterrylene in Naphthalene: A New Crystalline System for Single Molecule Spectroscopy in the Near Infrared

We report on a new system for single molecule spectroscopy in the near infrared:  dibenzoterrylene (DBT) in a naphthalene crystal. Its absorption band (758 nm) is interesting because single-frequency laser diodes may serve as cheap sources for near-infrared light. Single molecules in this system have a high fluorescence yield and narrow homogeneous lines and show neither spectral diffusion nor significant triplet population. All these characteristics make this new system very promising for future quantum optical measurements.