Polymer based lasers and amplifiers

Conjugated polymers are an important class of organic semiconductor that have now found commercial application in displays. This success has stimulated a growing interest in their use within other sectors, including TFT´s for display drivers and RFID tags, solar energy conversion devices, lighting, photodiode arrays for artificial vision systems, light sources and detectors for microanalysis, and optical gain media. This paper will present recent work performed within the Ultrafast Photonics Collaboration that addresses the characterisation of fluorene-based conjugated polymer gain media together with an update on their performance within laser and amplifier structures. Basic gain and loss characteristics have been measured by stripe length and stripe displacement amplified spontaneous emission measurements. Large gain coefficients/stimulated emission cross-sections, moderate losses and wide gain spectra can be readily achieved for a range of homo- and co-polyfluorenes. Blend compositions with Forster transfer Donor-Acceptor components can allow fine- tuning of a range of properties, including spectral range, excited state decay time, photoluminescence quantum efficiency, gain and loss coefficients and pump-power requirements.