Abstract

Over the last years a major effort has been invested in developing an injection laser based on light-emitting polymers. Many hurdles are related to the injection and transport of carriers through such a device, but there also many heavily discussed, unresolved issues connected to the emitting species itself. A very important experimental approach to explore these issues is the transient-absorption technique, where the gain or loss in the energy of a very weak, short probe pulse is measured, having passed through the sample shortly after the passage of a much more powerful pump pulse. This is a powerful technique, with sub-picosecond temporal resolution, broad spectral coverage and a considerable dynamic range. Clever use of these properties has led to insight in the decay of the exciton density, the ingrowth of absorption, etc, and thus to a better understanding of the bottlenecks on the road to a polymer laser.

© 2002 Optical Society of America