Stimulated emission from a needle-like single crystal of an end-capped fluorene/phenylene co-oligomer

Owing to light confinement, naturally shaped needle-like organic semiconductor single crystals of an end-capped fluorene/phenylene co-oligomer provide low-threshold unidimensional stimulated emission. The Figure shows a similar to1.5 mm long crystals, and photograph of the gain-narrowed normalized emission spectra from a polycrystal (dotted line) and a single crystal at 700 muJ cm(-2) (unbroken line).