Published online by Cambridge University Press: 25 February 2011
The enhancement of the third order nonlinear susceptibility χ(3)) of an homologous series of polycondensed thiophene based polymers was observed about photoinduced polaronic bands by a novel “pump-probe” degenerate four wave mixing echnique. Enhancement of the degenerate four wave mixing signal for more than an order of magnitude was achieved with response time of less than 25 ps. The intrachain polarons contribution is proposed as the possible mechanism responsible for the observed enhancement.