Interferometric Signatures of Single Molecules. T. Plakhotnik and V. Palm in Phys. Rev. Lett. 87:183602 (2001).  What the paper says!?

This resolves the coherent emission from a single molecule (and evidence incoherent fluorescence at higher driving). The technique is based on an interferometer of the Young slit type, that allows «the overlapping parts of the reference and signal beams [to] result in interference.» There is «a psychological barrier for all methods where a cutoff filter does not block off the laser radiation.» By removing this barrier and demonstrating interference of the emitter's coherent signal with that of the driving field, the Authors inaugurate the era beyond Stokes shift spectroscopy. The technique will be used a lot by the Sandoghar group.

The treatment is classical («{{onlinequote|as simple classical damped oscillators driven by a classical electromagnetic field}») and taken from Jackson's Classical Electrodynamics:

The modulus square of this formula is the fitting line in the figure.

The agreement is perfect. At higher power, the emission turns into the Mollow triplet (not observed, of course, but mentioned). The transition is called "0-0 emission" (meaning apparently that vibronic states and such, typical of a molecule, are ignored). A quantum version of their field amplitude is obtained (their Eq. (4))

The possibility of obtaining a hologram of the molecule is mentionned.