Amplification of optical pulse sequences at a high repetition rate in a polymer slab waveguide

Amplification of three short light pulses in a 140ps time window at 5kHz repetition rate has been demonstrated using a compact amplifier based on the conjugated polymer poly(9,9′-dioctylfluorene-co-benzothiadiazole). The amplifier was optically pumped and gratings were used to couple the signal into and out of the film. A gain of 22dB was observed for a signal pulse temporally aligned with the pump pulse in a 1mm waveguide. For a signal pulse delayed by 140ps, the maximum gain achieved was 14dB. The results are a step towards the use of polymer amplifiers in data communications.