Active polymer fibres doped with organic dyes: Generation and amplification of coherent radiation

The technology is developed for manufacturing active polymer optical fibres doped with organic dyes. Stimulated emission and amplification in the long-wavelength part of the visible spectrum is studied for rhodamine 11B, phenalemine 512 and substituted DCM pyran in polymer optical fibres. Lasing was observed upon longitudinal and transverse pumping by the second harmonic of a Nd : YAG laser. The gain in polymer fibres was estimated by measuring the intensity ratio of radiation of a master oscillator (dye laser) propagated through the excited (pumped) and unexcited (not pumped) fibre pieces doped with organic dyes. It is shown that the lasing efficiency of rhodamine 11B in a transversely pumped polymer fibre can achieve 36%. The maximum gain (25 dB m^-1) is obtained in fibres doped with phenalemine 512.