Coherent control of optical emission from a conjugated polymer

We have observed that resonant Rayleigh scattering dominates the emission f rom poly(p-phenylene vinylene) excited with photons at energies below the t hreshold at which excitonic migration is reduced. The intensity of the reso nant emission decays exponentially with a lifetime of up to 450 fs after pu lsed excitation. The coherent nature of the emission was confirmed by angul ar variations in the far-field emission intensity-bright and dark speckles. Persistence of a coherent polarization was demonstrated by coherent contro l using phase-locked pulses.