Subpicosecond relaxation in stretch-oriented poly (p-phenylene vinylene) films

We report the femtosecond laser studies of exciton decay kinetics in stretch oriented poly(paraphenylenevinylene) (PPV) films. Stimulated emission of excitons and stimulated Raman gain have been observed after 500 nm photoexcitation with 100 fs laser pulses. These are not observed when higher energy photons are used to excite the polymer.