Plastic Optical Fibers, POFs, are becoming increasingly important for applications in local area networks and automotive applications, as, comparing with glass (silica) optical fibers, they allow low production costs, easier optical coupling and higher flexibility.

Poly(methylmethacrilate), PMMA, is one the most used materials for POFs. However, their significant attenuation strongly limits the transmission distances.

Following previous findings that, upon dilution in a PMMA matrix, the stimulated emission of poly(9,9-dioctylfluorene), PFO, is shifted to longer wavelengths and that the stimulated emission could be switched off upon use of a second short pulse, prompted us to explore the use of these concepts in POFs and other optical devices. This could provide not only an amplification process but, in addition, an ultrafast optical modulation.

In this communication we report on the synthesis and characterisation of various conjugated polymers and oligomers that were dispersed in PMMA films and POFs, on the photophysical characterisation of the blend and copolymerised systems and on POFs fabricated with them. This investigation of new dopants was driven by i) the search of conjugated polymers showing gain in wavelength regions where PMMA attenuation is low, and ii) increase of dopant load while, based on the previous results, maintaining the dopant chains isolated from each other.

Acknowledgments: This work was partially supported by EU under the contract FP6-026365 (POLYCOM) and Instituto de Telecomunicações.