Ultrafast holography using charge-transfer polymers

Charge-transfer polymers are a new class of nonlinear optical materials which can be used for generating femtosecond holographic gratings. Using semiconducting polymers sensitized with varying concentrations of C-60, holographic gratings were recorded by individual ultrafast laser pulses; the diffraction efficiency and time decay of the gratings were measured using non-degenerate four-wave mixing. Using a figure of merit for dynamic data processing, the temporal diffraction efficiency, this new class of materials exhibits between two and 12 orders of magnitude higher response than any other class of material. The high quantum efficiency and metastability of the charge transfer enables tuning of the decay dynamics by controlling the concentration of accepters in the blend. (C) 1997 Elsevier Science B.V.