The effective stimulated emission cross-section spectra of a para-phenylene-vinylene polymer and of two para-phenylene-ethynylene polymers are determined by a fluorescence amplification technique. For these luminescent polymers laser action has been achieved in solution. The effective stimulated emission cross-section spectra are found to be small compared to the stimulated emission cross-section spectra calculated from fluorescence quantum distribution and fluorescence lifetime measurements. The laser excitation of the polymer solutions seems to form lattice relaxed exciton conformations extending over a few monomer units which are thought to be responsible for upper-to-lower-state stimulated emission and lower-to-upper-state (excited-state) absorption.
|Original language||English (US)|
|Title of host publication||Proceedings of SPIE - The International Society for Optical Engineering|
|Publisher||SPIEBellingham, WA, United States|
|State||Published - Dec 1 1998|