Dual amplified spontaneous emission and laser action from a model oligo(phenylene vinylene): comparison with the corresponding polymer

We report a comparative study of the spectroscopic and stimulated emission properties of a model oligo(phenylene vinylene) with those of the corresponding partially conjugated poly(phenylene vinylene). The model oligomer exhibits dual Amplified Spontaneous Emission (ASE) at 430 and 450 nm attributed to two independent vibrational modes in the excited state of the molecule. The corresponding polymer exhibits single ASE at 453 nm implying that in the polymer chains the amplification originates from a single vibrational mode. The efficiency of ASE and laser action is lower in the polymer than in the oligomer because of defects in the polymer chains.