Lasing from a dye-doped pendant drop and its precession

We have observed lasing from the rim of dye-doped ethylene glycol pendant drops. Spatial-resolved spectral measurements show that the lasing wavelength varies along a vertical rim of the drop. Time-resolved measurements indicate that lasing precession occurs within the drop. Various lasing patterns due to lasing precession are explained. The measured precession periods for different pumping points are in good agreement with the calculated values based on morphology-dependent resonance theory.